Okay, so I've decided to do some more work on that Univega I posted about the other day. I will not be putting my 105 group on it, but I would like to do some work to her. I plan on putting new brake levers on(found some decent looking Tektro levers on Ebay for $20). I would also like to upgrade the derailleurs as the current setup is very finicky. I've seen some neat old groups on Ebay, here is an example:

What do y'all think? This will be my first real attempt at doing any work on a bike and I have an experienced friend guiding me. I also ordered a few books on maint. so that will be a help.
As far as figuring out what is on the bike now, I cannot find serial numbers or anything, all the parts say is Shimano. Any advice? I think it's a 10 speed but I'm not sure....

Thanks!!

Shimano without anything else?

Do you have closeups? No numbers on the backs of anything?

10 speed would have five cogs in back, two cogs up front. 12 speed would have six cogs in back, two cogs up front.

East Hill