I was hoping to see a response for this because I too have wanted to read the original General Instructions.
I don't think this Instruction can be correctly called the 1960 GIRM. This would, rather, be the original General Instructions of the Roman Missal published for the Novus Ordo. I have read numerous references to it but have never seen the instructions themselves. Of course, if one had a copy of the "Sacramentary" published for the Novus Ordo back in 1969 or 1970, it would be printed in the front of that book. The reports are that the instructions were so theologically flawed (including outright heresy) that the instructions were recalled and a revision was introduced in just a matter of months. The revision was a typical Conciliar text that can be interpretted in many ways so as to please both conservatives and liberals. The original version was blatantly liberal and could not even be stretched by the wildest imagination to be consistent with Catholicism according to Father Cekada and others I've read.
I've never seen those original instructions myself though references to them are too varied and numerous to doubt that they existed.
I'l like to see these original instructions (in English) myself for purely academic reason but it does not appear they've ever been published on the internet having been recalled and replaced long before the internet was conceived.