Thanks for the comments.
Seat post: I'll have to check the make, I know it's german-made and I picked it up off ebay unused with 4 shims for next to nothing. I took the gaiter off it to fit in with the look of the bike. It's got adjustable oil/gas damping and seemed pretty good on yesterday's ride.
Inspiration: Having bought the frame on impulse because it was local and I wanted to work out what it was, I was inspired by some Tioga bars I had lying around which were on my '91 Karakoram when I bought it. I don't usually use risers, but I liked the coppery colour of them, which led me to think it would be good to try a build where everything possible was metal-coloured. Originally, I was thinking of trying to make it steampunk-inspired, but the craziness that would have led to would probably have led to a less practical bike, so it shifted to the more industrial-style.
Ride: I took it for the first time yesterday for the Hull & Bygone Byke Jumble ride:
http://www.retrobike.co.uk/forum/viewtopic.php?t=227380
and considering I'd not even so much as sat on it to check the saddle was the right height before that, let alone tested and tuned anything else I think it did pretty well!
It felt pretty good, though the riding position is a lot more upright than my other bikes and the saddle definitely needs to go back a bit as I didn't appreciate quite how much extra effort is required (or at least using different muscles) just from the seat being further forward.
I still need to sort out the gears, as the chain came off a few times and lodged itself between the middle and granny rings. It was doing this before (on the workstand) and a new middle ring has improved it, but it's still doing it occasionally.
The saddle and seat post took some getting used to, with different feedback, but they were very comfortable.
The headset came a
little loose during the ride, so I'll sort that out too.
Overall, it was harder work, but I really enjoyed it.
I'll be interested to see how well the rust inhibitor I used on the forks is working too.