Thank you, that's really interesting. Sorry about the slow reply, I am a bit busy at the moment.
I agree about the canti bridge, I've always assumed that a previous owner had the rear drop outs replaced and at the same time may have had a canti bridge removed along with the other cable guides, to leave it as a single speed with one set of guides for rear V-brake. (Alternatively, some of the Ritchey frames from the era did not have canti bridges.)I guess they may also have added the two holes that have been drilled in it - one in the BB shell, which I would assume was for draining, plus two in the headtube, which I have no idea about the logic for - although they allign with the top tube and down tube, so maybe it was something to do with the modifictions.
I guess one possible logical explanation I hadn't considered is that the cable guides aren't original, but were brazed on to replace bigger triple guides (such as yours) that were removed.
The Pacific Cycle Tours information is definitely interesting, because if you could speak with someone who was with the company back then they may well know where the frame came from originally.
The rear canti bosses look very similar, but as far as I recall, mine does not have any reinforcement on the headtube
[edit] I've found another photo that I don't think I posted earlier in the thread that confirms that:
The seatpost on mine is definitely 30.0 mm. It came with one that was too short for me, so I bought the IRD one in the photos to allow me to ride it, but was on the look out for one even longer and a better atch for the build for a long time and finally got a (modern) Reverse Comp Lite seatpost to match the other red parts. It's just waiting for me to get the bike out of storage and have the frame refinished.
This is really making me want to retrieve the bike, check the frame details again and get it powercoater ready to rebuild! It should be much easier for me to do now too, since I'm now working in the city I usually get powdercoating done.
