The G (G611 type) is available from both Silver Fox and DC Kits. Mine came from DC as a body only kit. I think it's the same master built by Mike Edge which may have used the Worsley Works etch as a basis. Can be made to pass the 1 foot rule with time and patience, but mine has developed odd warping in some of the thinner sections requiring surgery. Lots of flash around the buffers from mould tears and air bubble cavities around the axleboxes. But it can be worked on. I did consider buying the Worsley etch just to do a new frame but couldn't be bothered as in the end as subtle weathering should knock it back a bit.
Tenshodo/Hanazono spud's can work quite well with a good feedback controller such as a Gaugemaster HH, but at the expense of noise and heat. Plenty of room in the bonnet for lead to add weight, and some voids underneath for same.
It could be that resin castings for the Silver Fox rtr versions have been well cleaned up before painting - perhaps someone has one and can advise?