I wouldn't write off the blue and grey RFB as a poor seller.
True that it is non-authentic for the British Railways era as the converted vehicles only appeared after the introduction of the "raspberry ripple" and "swallow" liveries. However it would be an appropriate livery for a heritage train on a contemporary layout. The full size 1215 is currently in blue and grey livery at Whitrope where it acts as the static buffet on Waverley Route Heritage Association open days. As a WRHA volunteer, I had a customer visited last year who told me that he was employed by West Cost Railways who owned identical vehicles. 1215 is not owned by WRHA, as far as I know it is owned by Northumbria Rail who also appear to own rolling stock at several other sites, so could well be on the move again in the future.
So far the RFB is the only one of the new Bachmann coaches which I have pre-ordered.