Thornhill, eh - there's a name to warm my heart!
The Kerr Stuart is pretty, but seems familiar somehow, but I can't think why just now. (Got it - Keith Bucklitch loco design??)
Snowdon Ranger, well that would be popular I think, yes.
Tram locos though, can't see Roundhouse doing another of those, after Stanley.....and er, was it Finescale?? did a nice one a while ago.
Gelert Matt - Joy valve gear!