All 14 of the fully perforated GR-4/GT-4 serial numbers were published decades before Olszyk's great book, and we know where most of them are, scattered around the world. One belongs to 4-time POCA Prez Les Gray in So-Cal. There are supposed to be two Stradales (GR-4 perforated chassis street legal cars) one in Japan, the other in the Middle East, but no one has ever documented them.
The 25 factory built Gt-3 car serials are also known, as well as 11 more factory conversions done after the initial sale. There are two known to be on the West Coast. But the Gr-3 was also a home-assembly option so there are quite a few more Gr-3s than just ones the Modena factory worked on. And then there are the cars that only used some of the Gr-3 parts; 10" rear Campys were one part.