Thanks for the comments - they are very much appreciated.
The battle continues... I've attached the firebox/boiler/smokebox assemblies to footplate and cut away the valence jig. I would have liked to make the boiler/smokebox detachable if only for painting and detailing purposes, but again this approach has fallen by the wayside - mainly due to not thinking hard enough about it when the model was being designed and partly due to the angle between boiler and splashers. The boiler bands are scale thickness, cut from 2 thou brass shim with a scalpel!
One picture in particular shows the interface between frames and footplate. The overlap is quite convincing. It also shows I was forced to remove the reversing shaft and the top part of the bearings as the operating arm impinged on putting the body onto the frames. Careful use of the resistance soldering iron made this quite straightforward, but I was still fearful of the bearings shifting. It can all be reinstated during final assembly.
After checking my drawings, and looking at photos numerous times I found that the handrails on the cab rear are tapered. They are fashioned from clock pins (which are an excellent source of such items and made of nice free machining nickel silver) of the correct size, cut to fit each gap with a spigot and socket to align upper and lower parts. Little turnings make up the widened top and bottom portions with the upper bracket fabricated as required.
I've established the valence and steps for the tender, and put the beading along the cabside and tender top. I don't have a rolling mill, so these are formed from etched strips with a convenient groove down the middle. I solder the flat workpiece onto the edge of some sheet metal, clamped it between my bending bars in the vice, and then profiled it using files and emery paper before removing and cutting/forming to shape. It seems to be successful and repeatable but a bit labour intensive.
Time for some fittings (and everything else).
Best regards
Tom