I have a Canon 70-200 f4L IS that has a small amount of either back focus or front focus, not sure what. Otherwise it makes tack sharp images. I got a bunch of 67mm filters got a red, polarizer, UV and caps.
I'm looking for an ultrawide for Canon or something Nikon-mount. 17mm at least.
I also have a Nikon 85/2 AI-s I would trade for something Nikon and UW maybe a 20/4 or something like that. If you have Mamiya RB backs or 120 film (those of you hoarding Tri-X 320 I'm looking at you) I would accept those on top if your trade is worth less.