Why are all the posters on this missing the obvious, all r-t-r stock is just over 4ft gauge, not 4ft 8 1/2in. If people are prepared to accept that compromise then leave them to it. If people want to build an accurate brass kit of an LNWR coach to go with their re-gauged Bachmann Coal Tank then that is their choice. Running the same engine out of the box with a rake of generic 4 & 6 wheelers is not a crime.
The hobby is being promoted at the moment by a national channel TV series on which I am sure I saw a Coal Tank on Mars and a Sentinel diesel shunter on a Swiss mountain railway.
There is room for excellent scale modelling for people who have the skills, time and patience, and for people to build a layout and run what they want on it straight out of the box. Hornby O gauge used to make an 0-4-0 tank in every big 4 livery, and a detailed Princess Elizabeth. There is enough intolerence in this country now without taking it into the model railway community.