Excellent stuff, Tony! Thanks for posting that.
The Kitson is actually running on two cut-down U class chassis that have been fitted with pivot mountings, not Mallet ones. Sound and DCC is a Massoth XLS (programmed for a German Mallet) in the bunker, with a big Visaton speaker under the "coal load".
Incidentally, we have no idea of the provenance of the Kitson model - I bought it (in analogue form) from Tony, who had in turn got it in an auction job lot (along with several other scratchbuilds in plasticard, but this was the only brass one, so most likely not by the same builder). It's beautifully built but quite obviously from scratch - it's all brass except for a steel pipe for the boiler, and the analogue wiring was quite odd, using the whole metal body of the loco as a common return! I stripped the power units off and insulated them from the body, rewiring it so I could chip it for DCC and sound; the only thing I haven't yet done is to reconnect the lights, which were originally run off a 4.5volt flat "bell" battery in the bunker.
If anyone has ANY idea at all as to who might have built it, or when, I'd love to know.....
Jon.