Ha! I have one too, Mike, and a lovely old thing it is. Mine is the Nikkor-S Auto from 1971/72 that has been converted to AI, so it is equally at home on my old Nikon F as on the D700.
Check your serial #, and go here to see when made.
I need to get out more with mine, but here are some samples at f/1.2 ...
The AI and AIS 50/1.2 are the same optically. The nine blade aperture is the main difference with the AIS version, and it has no real difference on the image unless there are specular highlights in the background which show up the shape of the apertrure.I bought my 50mm f/1.2 some 25 years ago, so the "much newer to me" 55mm is more often used these days. Since I have the 7 blade AI 50mm, I don't think there is much between them. The newer 9 blade 50mm is said to be better, but I guess its just something they say