Along with RCA & GE, Dumont produced B&W cameras in the 40's & early '50's. As for TK-40 & TK-41 color cameras, UCLA TV & Radio Archives has 3 of them. And TV camera collector Chuck Pharis has several of all types of 40's, 50's & 60's era cameras.
http://pharis-video.com/index.htm
I also know of at least 2 other early RCA color cameras in private collections. A picture of me standing behind a collector's TK-40 can be seen (last item) on my web page.
-Steve D.