Haven't had any luck identifying it so far. It's definitely not a Surly, the welds aren't anywhere close to that level of quality. A friend who is quite skilled at identifying frames thinks it is a mail order bike of some sort. I'm also kinda thinking that with the very low serial number and the somewhat lackluster welds, it may be one of a framebuilder's first attempts at tig-welding a frame. Even if it doesn't have an identity, I'm enjoying it quite a bit. I swapped to a set of drops tonight, I'll post another pic once I've swapped a few more things.