Any idea where to find Micro Seiki tonearm parts?

The counterweight, and arm wand.. For ANY TT are nearly impossible to aquire.
My rule is NEVER buy a TT missing the spindle, platter, headshell, armwand, or counterweight!! The TT may seem like a great bargain, but trust me, it is NOT!
In general, do not buy a TT missing anything!(except TT that are designed to accept other arms, then no arm is ok)
Anyone with a spare part, is NOT gonna sell it. Unless you can make an offer they can't refuse. ((they are your mother in law...etc..)

As a Micro-Seiki collector, the best place to find parts is to join the Micro-Seiki user group on Yahoo:

http://groups.yahoo.com/group/MicroSeiki/?v=1&t=directory&ch=web&pub=groups&sec=dir&slk=22

They are a great resource and have access to many parts and information. I am a long time member.

also try these folks : http://www.my-micro.de/

The counterweights or their replacements are occasionally available in Japan. I'd have thought a 'NOS original armpipe screw' would be impossible to find, but could probably be replaced with another '3rd party' screw. I will take a look around for the C/W.

Elizabeth, the other way to do it is to only buy TTs where the parts can be found. For Micro Seiki 1500-series TTs, and things like Garrard 301s, all parts can be found given a bit of time (and the willingness to part with money for them).

Donshoemaker,
For the weights, there is a guy here who sells MA-505-series main weights and sub weights (his store is a metal workshop). The main weight is JPY 9,000 (about US$90), and the subweight JPY 1,000 less (about $10 less). To me that is a fair bit (shipping would add a bit but not much) but 'parts arms' go for more, and I don't know what a machinist where you are would charge. There is another guy who does MS parts and I will try to get his name/site and post it here soon.