I'm looking at buying an enlarging lens for my Beseler 45MCRX. The one that I see is a Schneider Kreuznach Componon S 80mm f/5.6. The problem that I'm trying to get out of the person is how big the threads are on the back. I need an 80mm lens that has the 39mm threads on the back that uses a jamb nut to hold the lens against the lens board. If anybody could help me out, that would be awesome. Thanks!