I will look that up for you and let you know. I recall that it is some kind of “copy” lens because it has a better depth of field and lack of linear distortion that works very well with small flat objects.
I still haven’t wandered into my office to look at the lens, but I found these two pictures from another thread. https://www.cointalk.com/threads/post-your-coin-photography-set-up.229658/page-9#post-2938493 Can you identify it based on these?
I might have the largest 1960's collection on earth. I'm certain I could fill 10+ pages of this thread. LOL
Plus I have a full roll of small dates acquired over the decades as I found them at dealers and shows.