This compares the F1.2 & F1.4 lenses (MC & MD, 50mm & 58mm)
And here, describes Minolta MC/MD lenses used with 4/3 olympus DSLRs.
Remember also, that other manual focus lenses are not in so much demand these days either. I bought a Tokina ATX 80-200mm F2.8 lens for around $100, for a Nikon Ai mount. It's a simple matter to buy a Nikon to 4/3 adapter for that!!! And remember, because it's a 4/3 sensor, the equivalent is 160-400mm F2.8 !!!!!!!
It opens up a whole world of "obsolete" manual focus lenses!!!