This week with modelling mojo in the ascendant I've been putting together an 0-16.5 narrow gauge loco for a friend of mine. It's a plasticard scratchbuild on a sweet running Bachmann HO chassis. Based on the Kerr Stuart diesel which spent some time on the WHR before being exported to warmer climes it deviates from strict prototype accuracy in that it has a more typically 'British' cab which is itself stretched a touch to accommodate the motor. However I think it does a pretty good job of representing the characteristics of the real thing.
Though it's been a pleasurable build, there have been times of head scratching partly/mainly because I'm not used to working in the larger scales and I have no instinctive sense of the size of things.