Mystery ebay find

Here's a unmarked aluminum bike I noticed on ebay recently;



Of course, I need to figure out what it is. Some companies have easily indentifiable characteristics. GT's Triple Triangle, Cannondale's fat tubes and filed joints, Rocky Mountains' pre-93 wishbone. But this one doesn't show anything really. It's pretty generic; plain dropouts, top mounted cables, and the cable stop on the seatstays make it (roughly) before 1997.



That seatpost bolt is not very common though. That might help ID it.

And then there's this;

What is going on under that BB? Is it an eccentric? Doesn't seem likely on a bike this old. Some sort of press in BB that is held in by those bolts? I think Fisher and Klein both used them, but the rest of the bike doesn't seem to match up with those companies.

I want to say it's an American, but I'll have to research it some more....