Things I learned building the Bulldog locomotives footplate:

• You shouldn't bend the splasher faces up before putting on the valances. It makes balancing the resulting sheet upside down a whole lot more difficult. Not impossible thanks to a combination of bits of wood and lolly stick, but more difficult.
• The supplied plan is not 4mm scale. It's just a little bit bigger. That is quite annoying.
• The valances fit behind the the rear beam and not at the side of it. Do this and they are too wide for the front buffer beam.
• The bolts are 10BA. More than adequate and a lot easier to fit than my normal 8BAs since the holes don't need opening out.
• The splasher tops are fiddly but doable. The trick is to put the first sharp bend in place, tack the strip and then work it around the splasher face. Tiny amounts of solder mean little cleaning up is required. I'm quite pleased with this.
• The chassis is a touch too long but can be shortened easily enough to fit. About 1 and a bit millimetres I think. Just make sure you take it off the right end so the wheel centres and splasher centres line up.

Of course I knew some of this already. And even remembered it before I started. And only had to take the valances off once...