I stumbled upon this thread, but I found it interesting. Yes, 3200 rifles would mean one per week for 61 years, but maybe Cornell was efficient enough to knock out closer to 2 per week. I don't know, but maybe Marvin will chime in on the topic.
I also recall reading that Cornell Kemper started off rebuilding rifles out of broken ones, with people sometimes sending half a dozen old guns to be restocked and rebuilt. He started out in cabinets after WWII, so his woodworking talent led to restocking. I think he did that for a few years before building his own rifles.
All I know is that my own Cornell Kemper .45 was built around 1975-ish, according to Marvin, and though it is not overly fancy, it is a well-built rifle, and still my favorite shooter (Douglas XX barrel). I think Cornell mainly stuck to a pattern that he could reproduce very efficiently, with his signature Roman-nose comb and Berks County profile.