I have the MD Zoom 70-210 1:4 (55mm filter) which is the beercan manual focus model. It's a push/pull zoom with stellar distance markings. Lovely glass, but a big optic, so at 210 handheld, you need some serious shutter speed for sharpness. It should come with a reversible clip-on lens hood engraved with the nomenclature.
You'll find the main list here:
My understanding is the MD glass was slightly better, particularly due to superior coatings compared to the much older MC glass.
They are common and a terrific value. Under $100. I paid a pittance for mine in mint condition and just used it at the beach 2 weeks ago.
I find that these long zooms tend to be in better shape than shorter FL's, probably because they are so intimidating they stay in the bag!
I'd stick with the Minolta brand. Proven quality. Great prices.