It would take a special kind of collector to put much value on this mid-grade frame over its utility. If you could find that collector, sell it to him and get a better frame to build. Maybe consider taking up Seabass' offer? This one doesn't look like it has the 'squashed' tubing of other (Yamaguchi built) Shimano Aeros I've seen online, so maybe it is just a re-stickered generic frame? Here's a link of one I'm talking about, with the squashed tubes: Picasa Web Albums - Jeff Bell - Shimano Bicycle (it a gallery of ten photos, so you can click through if you want to see more than just the first one)

It's hard to see from the pix, but it doesn't look like the chrome is in very good shape, either. Detailed pics would be a big help, as usual.