Hi, After looking for at least a year I've failed to even find one of these for sale. Is this a super rare enlarging lens, or was it just not marketed in the US, or what? Apparently it is was also sold as either 55mm f/1.9 Computar, or as a 55mm f/1.9 APO-Computar. I became interested after reading Ctein's review that showed how well the lens does at larger apertures. That's a quality that would come in handy to cut print times for super dense negs/possies. Any hints for finding one, and are they worth hunting for?