I wanted to join this thread and thank all those who have compiled such extensive data on the 945 and its variants. With that, this is an update on the two models I have. You'll see up near the start, CFR0330 (170152) which is my first 945 (those pics, much better than mine) from the auction website 11/2019).
The most recent (11/2020) was the RSA1839, 170173. I noticed both models (when apart/field stripped), the major components are numbered (coded). I hope you can see that in the pix for the 152 variant. Also, on one of the data tables, the 945-1 (170173) does not have the billboard (showing the number 945; just the PC label). Wonderful firearms.... (still learning more each day with all of the threads!)