Thanks for all the replies.
The seat tube is basically square, and my (fragile) understanding is that it's larger than any standard clamp-on, so I can't just throw a normal clamp-on on there. My initial thought was like HillRider's - and this is where it's a little murky. The XX FD that they put on was a kind of custom clamping from what I can tell. There is a related issue that due to this adjustment, there is very little clearance between the clamp and the back tire. So one thought (from the shop) was that the FD might be moved up but unclear how this affects that clearaance issue. I'm new to SRAM stuff but it's compact-ish (would be nice to have option for standard but I can live with a compact).
Sorry I don't have a pic because I dropped it at the shop yesterday. You can see the frame here:
http://www.specialized.com/us/en/bc/...01&scname=Road
I don't have any welder friends, but that is an interesting idea. In retrospect, for doing Mt Washington, I could live with just a fixed 24 on the front; outside of the first 50 yards there aren't any sections for which you would shift more than a cog or two (for me anyway).