Hi, I'm hoping someone can tell me what's going on with one of my Olympus OM System lenses. Specifically, the 65-200mm f/4 Zuiko Auto Zoom. I have an OM-1 and an OM-2, both with 50mm lenses. Either 50mm fits on either camera body, as expected. The 65-200 does not fit on either of them. When I try to mount it, the lugs align and it seems to mate but, when I try to twist it into position, it will only turn about 1/3 of the distance required, at which point it feels like it's binding. The mounts are visibly different between the 50s and the zoom. The two 50s are the same design, but the zoom does not have the "OM shield" and it has spikes where the 50s don't. I'm not very good at this sort of thing, but I tried to take photos to demonstrate what I mean. Here is the trio. This is one of the 50s, showing the "shield". This is the zoom, with the "spikes" on the left. And, just to prove that I didn't accidentally grab the wrong lens, here's the other end. I have several other OM lenses. All of them except my 135mm f/3.5 have a "shield", though the size varies. The 135 has no shield, but also lacks the spikes on the zoom's mount. All of the other lenses mount without any trouble. I don't believe any of them have that SAEA marking, either. Any idea what I'm running into, here? Thanks!