My brother gave me his Minolta kit, and while I may try the camera out someday my main interest is in the 21mm Tamron lens, S/N 632183. My guess is that it is about 40 years old. Since I long ago despaired of having a 21mm Zuiko, I'd like to try this on my OM's. The question is, what type of Adaptall would this take? The lens has a pretty primative band clamp with a small screw that appears to hold the Minolta adapter. But after removing this clamp the adapter still does not seem to want to move or loosen in any way.