Oh, go ahead and hack it to fit whatever camera you want to shoot it on. It's just stuff, a hunk of metal and glass, and there are plenty more around. I saw twelve on eBay alone. Save your compassion for living beings
I also would prefer to shoot it on a small and light screw mount Leica. Never liked the Contax and Nikon rangefinders cameras. They're too big for 35mm format, and the focusing mechanisms seem needlessly complicated. Keep in mind the Opton is a large diameter lens and you might end up w/ some of your viewfinder blocked on a screw mount camera.