Thanks a lot, this answers exactly what I wanted to know.
I guess old cinema projection lenses are all designed for 50 ft to 300 ft, and I probably will not find something used that can handle a shorter focal length. 15 ft is really the upper limit for me in terms of size, and a soft focus does not sound like a good thing. Also, I was just going to use it on a LT-150 (or equivalent), and it probably projects a large image because it is designed for presentations. Probably would not have fit.
And I was going to pay $200 for it..... Thanks!
P.S. Yes, I saw Alan's thread, and that was when I started looking around for this.