Well, I've missed Christmas, obviously. Maybe it'll be done for Christmas 2016...
I did manage to spend a few hours on it last night. I'd been thinking for a while about fixing the LED to small pieces of PCB, but I didn't think standard 2.54mm pitch Veroboard would fit (four holes would be ~7.6mm, and the holes are only 6mm), I considered getting some 2mm pitch board, but it's remarkably difficult to find in small quantities. I also thought about getting PCBs made, but it just seemed too expensive.
In the end, I thought I'd at least try with some scrap 2.54mm pitch board I had lying around and, well it's not to bad. The board stands a little proud of the rear of the letter, but that's OK. I little work with a file to widen the hole at the appropriate place and it should be OK. The upside is that it is so much easier to solder solid-core to Verboard that it is to try and lay-on not just one but two pieces of wire on each individual leg. Plus the legs were getting dangerously close together for something fused at about 2A.
I had one mishap with an LED that went pop (I could have sworn it was in the right way around), and another that didn't solder correctly, but I got five done in the end and I was starting to get the hang of it. And the little shards of Verboard look like Shreddies.
Only another 39 or so to go.