Very interesting.
If it is true, it certainly was not observed by SSPX priests in my neck of the woods.

An SSPX priest here in Europe told me, that there is a communication from the General House on the subject of requiem.
It states that a private requiem for Bishop Williamson is possible, but not a public one.
"Private" in this context means that the intention for which the Mass is being offered is known to no one but the celebrant (and the the donor of the stipend, or to very few other person). The opposite would be an announced Mass.

Anyone who knows a little about canon law will notice that this order corresponds to the treatment of excommunicated persons. In the Codex Iuris Canonici of 1917, c. 2262 states (in English translation):
 
Canon 2262
 
§ 1. One excommunicated is not able to participate in the indulgences, suffrages, and public prayers of the Church.
§ 2. Nevertheless, it is not prohibited:
1.° For the faithful to pray privately for him;
2.° For priests privately and avoiding scandal to apply Mass for him; but, if he is banned, only for his conversion.

Yes, there seems to be a diversity of opinions in the SSPX regarding this.
Perhaps the older priests and/or those ordained by him are the only ones offering requiems for him?

Unofficial.
Photo of Cardinal Rampolla, who was elected Pope, sort of...

https://www.alamyimages.fr/photos-images/cardinal-rampolla.html?cutout=1&sortBy=relevant

This might be the photo...look at his demeanor and vestments.
St Pius X, pray for us!

Duh. I know what Modernism is. Pope St. Pius X knew what Modernism is. But he never said that Modernists were outside of the Church. He never said that sedevacantism was the answer to the heresy of Modernism. He never mentioned sedevacantism at all.

They certainly don't follow the Code on donations.

(LifeSiteNews) — Bishop Richard Williamson died today at the age of 84 in a British hospital surrounded by close friends and clergy following an unexpected brain hemorrhage last Friday. His Excellency was administered Last Rites by an assistant priest at his residence in Broadstairs, England immediately after the incident.  
According to an update given on social media by those close to him, Williamson died at 11:23 p.m. GMT, and his “final agony was only a matter of minutes.”
Williamson was one of four traditional Catholic priests consecrated by French Archbishop Marcel Lefebvre (1905-1991) and Brazilian Bishop Antônio de Castro Mayer (1904-1991) in 1988. 48-years-old at the time, Williamson — who was Lefebvre’s initial choice to be consecrated alone — was one of four auxiliary bishops consecrated for the Society of St. Pius X. Spanish priest Alfonso de Galarreta, now 67, Swiss priest Bernard Fellay, now 66, and French priest Bernard Tissier de Mallerais, who passed away last year at the age of 79, were consecrated along with him. 
Dubbed “Operation Survival” by Lefebvre, the undertaking prompted the Vatican to issue a decree stating that the parties involved had incurred an automatic excommunication. The SSPX contested the validity of that pronouncement and in 2009 Benedict XVI lifted the punishment. 
Williamson was born to John and Helen Williamson in Hampstead, London in 1940. Raised Anglican, he received a classical education at Winchester College and Cambridge University, where he came to have a deep love for poetry, music, and literature, especially Shakespeare and Mozart. In his 20s, he taught language for two years at a boy’s school in Africa before returning to his homeland and converting to Catholicism at the age of 31 thanks to praying the rosary. He is survived by one remaining brother. 
At the insistence of an Irish priest, Williamson enrolled at the flagship seminary of the SSPX in Switzerland in 1972 after having previously tried his vocation elsewhere. Historian and close friend Dr. David Allen White recounted Williamson’s conversion story in his biography . 
Having proven himself to be an effective educator, Williamson was asked by Lefebvre to serve as the rector of the U.S. District’s seminary beginning in 1983 after nine American priests left the Society. Williamson immediately began publishing monthly letters on current events, politics, and similar topics related to the crisis in the Church. Among other things, he was an ardent promoter of the writings of St. Paul, the alleged Marian apparitions in Garabandal, Spain in the 1960s, the “seven ages of the church” Our Lady of Akita, and praying 15 decades of the rosary every day. The essays were a precursor to his Eleison Comments weekly articles. 
Williamson oversaw the formation of hundreds of young men at the U.S. seminary, which under his direction in 1988 relocated from Ridgefield, Connecticut to a much larger, former Dominican monastery in Winona, Minnesota. Many of the impassioned and lectures he gave on , , globalism, economics, and other eclectic subjects like women wearing pants and The Sound of Music can still be found online. He was reassigned to the Society’s seminary in Argentina in 2003 where he remained until returning to England in the late 2000s. 
Tensions arose between Williamson and SSPX leadership over how to respond to an international media frenzy that occurred after he told a journalist in 2008 that he believed “no gas chambers” were used in Germany during World War II. The remarks, which he later called “imprudent,” caused headaches for Benedict XVI who had just lifted the 1988 excommunications of the Society’s bishops.  
For the next four years, Williamson was without a public assignment. In August 2012, he made an unauthorized visit to a then-SSPX-aligned Benedictine monastery in Brazil to perform confirmations. He also grew more vocal in accusing those who were in positions of authority in the SSPX of betraying Archbishop Lefebvre’s principles by seeking a practical accord with “unconverted Rome.” Letters between high-ranking SSPX clergy debating that subject were leaked to the public at the time, which lead to several books about the group’s inner workings. 
Williamson was asked by then-SSPX Superior General Bishop Bernard Fellay to halt his weekly newsletter, which he did not do. He was eventually [url=https://stmarcelinitiative.org/farewellwimbledon/]dismissed from the Society in October 2012 by a vote at a general chapter meeting that he was excluded from attending for not showing due “respect and obedience to his lawful superiors.”  
In the ensuing years, a small number of SSPX priests either resigned or were asked to leave for expressing views similar to Williamson’s. His Excellency coined the term “the Resistance” to describe what he called a “loose association” of clergy who were “faithful” to Archbishop Lefebvre’s approach toward “the Conciliar Church.” The number of Resistance priests worldwide is estimated to be more than 60 but not higher than 90, though sympathies for their thinking still seems to be present among some clergy in the SSPX, which since the early 2010s has said that a canonical agreement with the Vatican is owed to them in justice and that “prudence” will dictate what its terms would look like. 
In 2015, Williamson consecrated French priest Fr. Jean-Michel Faure. Faure had been asked by Lefebvre to be consecrated in 1988 but turned down the offer after stating he believed he was unworthy. The SSPX denounced the move in a press release, but the Vatican has never commented on it. Faure has since established the Society of the Apostles of Jesus and Mary in France. Similar apostolates linked to Williamson have been founded elsewhere across the world. 
During the last 10 years of his life, Williamson consecrated at least bishops and ordained more than a dozen priests, most of whom live in Europe, but some of whom reside in the United States and South America. More recently, he offered praise for Archbishop Carlo Maria Viganò. Williamson had been publishing his weekly newsletter, appearing on , and posting sermons to his YouTube channel as recently as last Sunday. Scores of Traditional Catholics on social media prayed for and expressed gratitude for him in the days prior to his passing. 
LifeSiteNews encourages readers to pray for the repose of the soul of Bishop Richard Williamson.

But what is to the Cardinal's right? The skirting of the small table. Is that also part of his vestments, or tapestry, or what...?