I've got a nice Russian-made 300/4.5 lens that fits the Mamiya 645. (It looks like it uses some sort of interchangeable mount system with a 645 mount on it currently.) It's a manual aperture lens - you preset the aperture at the front of the lens and then open it to compose/focus and then close it to shoot. It may even have been a cine lens originally?
All in all it's in very nice shape. I can see some tiny imperfections on the front element, a few specks of dust internally, etc. but being such a long lens none of that is going to affect picture quality. It's some nice BIG clear glass - much heftier than the relatively wispy Mamiya 300/5.6. Comes with what looks to be the original screw-on metal front lens cap, and a standard Mamiya rear cap.
I'd like to get $150 plus shipping for this. Figure $15 shipping in the US, or we'll figure it out internationally. Won't be cheap, this lens is *heavy* and will require Priority Mail International shipping.
Duncan