Evidence (didn't want to overly hijack crowriver's thread for purposes of blowing my own bikebuilding trumpet!)
Sunday efforts got it this far
I finished the job tonight after spending an age trying to pack more beer can in behind the stem clamp to keep the bars held firm and took it for a test spin round Arthur's Seat.
So the saddle rotated back a few notches leaving it at a rather jaunty angle and the fork crown race needs a good thump with a setting tool - it's causing a bit of a shimmy and a judder just now when I brake. But apart from that everything seemed to work and my biggest worry - the back wheel not clamping in tight enough and the chain slackening off - didn't happen, even grinding up the hill. The dropped bullhorns gave a lot of new hand positions to try out and I found them great for slowly winding up the hill out of the saddle.
With thanks to chdot for parting with the frame and recombodna for swapping me the bars and to smudge for the excellent advice on using beer cans as shims.
Oh and I've just realised that (the headbadge and decals aside) no (new) bits were bought off the internet for this bike! Thebicycleworks, Veloecosse, EBC and Bicyclerepairman did the necessary. Thebikechain may yet flog me a blue Brooks to join the part.