Micro Seiki MA-505 variants - any oracles around?

Wow! Impressive knowledge of that subject.  I once owned what was at least a Mk II version and foolishly sold it without ever having used it. I would only add that for the Japanese, "S" is not always an indication of silver wire.  For example, the Fidelity Research tonearms that bear an S suffix are not necessarily silver-wired, unless there is a separate label so indicating.

Wonderful stuff br3098, thank you so much for taking the time to write it all down!
I recently picked up an MA-505X, seemingly in mint condition (time will tell I guess) at a relatively reasonable price, but wasn't entirely sure exactly what I was buying due to the plethora of models in existence and an almost complete lack of dependable information.
I was under the impression that the 505X had silver wiring, but whether or no makes no particular difference.  I've never owned one but enjoy the sound of it a lot in a friend's system, so I decided it was time to check it out for myself.
Thank you once again, I'm most grateful.

Guys,

I forgot to add that (apparently) the XII and LXII tonearms also featured silver wiring.  Again, color me skeptical if you own one you tell me.

But all in all the MA-505 line are very good tonearms; if not equal to those in the highest class.  I find them to be unequaled on classic Japanese DD and belt drive decks, which is what they were designed for.

Indeed, I'm sceptical too.  Fortunately I don't particularly care and in any case I'm unlikely to ever find out unless the arm turns out to be defective and needs to be disassembled.

Mine will by necessity be mounted on a Spacedeck, but presumably it will perform well there too.

How do you like the performance of the arm? What Cartridge are you using?