My first thought was Habanero as well, but the two that I have had do not have serial numbers. Could have been added by an owner along the way. The welded in bottle bosses is something that Habanero does. Is it a 27.2 seat post?
I am fairly certain it is a Habanero team issue based on the dropout details and the downtube but I emailed them to make sure. I am not sure about the seat post size, the one that came with it was way too small and I haven't tried another one.