interesting fixturing -- I like it. I'll be interested in knowing how that seat tube/down tube joint holds up. It looks like the cleanup might have been a little heavy-handed. You really don't want to cut into the tubes at all.
Looking good! You painted it yourself, too? And it`s going to stay single speed? I can`t tell for sure, but in one of your earlier pics (bike leaning against a toolbox with no seat stays yet) it looks like a derailler hanger.