Glad they're finally waking up and seeing what has been obvious to everyone for decades.

As far as I'm aware it only became obvious to people after the Dimond brothers broke the story, for which no one gives them credit just like so many converts to the true faith came through them but won't acknowledge it after they reject EENS dogma.

You are right here.  The first time I heard this was from the Dimond Brothers.  My initial gut reaction was that it was a kooky conspiracy theory--like all the others.  It was actually after realizing that the difference between a conspiracy theory and the absolute truth so often time that I relooked at their presentation and decided that they were making some really good points.  I have never heard why Chojnowski decided to get involved in the matter, but his organization has pretty much definitively proven the case.

As a side note, the time between "conspiracy theory" and "truth" seems to have shrunk over years from decades to weeks and sometimes even days.

My grandparents found out about the description issues of Lucia in the book Our Lady of Fatima by William T. Walsh (published 1954). Mr. Walsh met with Lucia in 1946. They also found about it more from Horvat.

https://www.traditioninaction.org/HotTopics/g12htArt2_TwoSisterLucys.htm

So, where does that leave the Church with regard to Fatima?
Where does that leave the Catholic Church in the eyes of the world?
Will they say its a made up religion that needs frauds like that?
Read the comments to the Fatima centers.

It all seems pretty much open and shut. 

Best case scenario, the real Sister Lucia died naturally, and for whatever reason, they enlisted another woman to play the part of Lucia, either (a) to have a convenient shill for Newchurch, (b) as good public relations, to be able to trot out a living Lucia on demand, or (c) both.  Worst case scenario, they either imprisoned or, God forbid, killed the real Lucia, to be able to have the kind of shill I described above, to keep the "real Lucia" from denouncing Newchurch, and/or to keep wraps on what the Third Secret really was. 

Being able to have "Lucia" say that the consecration of Russia had taken place, and had been accepted by Our Lord and Our Lady would have just been icing on the cake.

I don’t believe she died naturally but was likely murdered.  I also believe she was still alive in 1957.

So, I don't believe she was still alive.  Why?  Because Our Lady would not have subjected her to the Novus Ordo Mass, etc. ... a consideration lost on them at Fatima Center.

His objection that it would be hard to get an imposter to become a cloistered nun and live that life 24/7 is weak.  They could have just enlisted someone who already was a nun, or else not had her actually living in the convent except for those occasions when she needed to appear.