I have an old Pentax 500mm f4.5 manual lens from my very seldom used 35mm system and I was thinking that it would be great if the lens could be adapted to use on my Hasselblad. The only time I seem to use my 35mm anymore is for long telephoto shots. How difficult -if even possible- would it be to adapt this lens for use on a Hasselblad (2000-Series)? The rear part of the lens behind the aperture can be easily detached, so I hoping that this is more of a machining problem. I am assuming that coverage/vignetting won't be an issue(?). Is there anyone out there that has done this?