Thanks for the kind comments. Quite a way to go yet, though.
I agree, Larry, the C13s were surprisingly large locos. Like you, I assumed a 4-4-2 tank would be quite small, but it's turned out quite chunky.
Brian, it has a High Level coreless motor and Roadrunner+ gearbox. I don't have an LNER layout, it's ex_LNWR, but modelled in mid 1950s BR. 67421 was shedded at Gorton in the mid 1950s and frequently worked the Guide Bridge to Oldham or Stalybridge push-pull services. I've just imagined that either of these could have been extended to Delph (or Holt, as my imaginary version is called). Such workings would have been perfectly feasible with the existing trackwork although they didn't actually occur.
Dave.