Bought a conversion kit from EdMika in Ontario, but the conversion took 3 days since the rear stationary lens wont come off yet
aperture linkage parts came off without a reason after some popping noise when I took the mount base. UUGGHH! It was a scary
moment to think about loosing the lens and new conversion kit all together. Since the spring ring which holds the aperture linkage
metal wont be placed no matter how. So I had to make a pressure plate to push down the aperture linkage metal using a Prakticar
camera spare mount and had to ply the rear lens from the FD mount. That was a kind of difficult not for faint-heart person's job.
(guess someone opened the lens for some reasons, but could not make it back to the original shape, then quickly sold it to the shop)
(me visited this used camera shop in Shinjuku Tokyo, found relatively less expensive this FD85/1.2 lens and bought it. that is why!)

Note: The original rear lens is stationary, though this EdMika's rear lens travels a bit particularly goes forward when focusing to
near subjects. I have no idea whether this behaviour affects the image quality or not, though it does not seem to have the effect.
Yes, when focusing to closer to infinity the rear lens moves to its original position. This is his ingenious invention/trick I think.
Also this rear element is not a near flat lens, its both surfaces are noticeably convex that is why I was worried about its move.