Nigel, thanks for the good advice. Your point about wheels for scratch building locos is a very good one which I hadn't really thought about, really in starting off in N fiNescale I was still in the mode of thinking about rtr and trying to avoid re-wheeling, but as you rightly say I'll need to scratch-build if I do the Cambrian. I think I feel a 2FS layout coming on! Anyway, this is helping me to get my thoughts clear, so thank you.
Also looks like I need to be saving up for a Robocutter or Silhouette!!
Anyway, in danger of diverging from the intended topic, so I'll hand the thread back now.
Andrew.