Thanks I'll take a look.

I've now got a diagram of the underframe for the original one, and what seems to be correct sides, but unfortunately the roof vent detail is omitted.

It's etched on 8thou brass. I normally use 8 thou fro N scale coaches - its strong enough but thin enough for the detail in most cases. SECR stuff is a bit hairier and that generally needs two layers of 5thou or there abouts. It's currently sitting on a pair of Farish bogies - I shall probably have to either make some fold up etched ones or overlays after double checking the 2mm SA shop.

More LB&SCR coaches in N/2mm would be good from all sources !

If you want to use 2mmSA parts then the axle length is 12.25mm and there are a set of drawings of the recommended design including 2mmSA bearings at http://www.2mm.org.uk/standards/underframe.htm and the 2mmSA also has N scale wheels to that spec which *just* clear the etches built to that diagram. There are also generic 2mmSA bogie fold ups designed to get the cosmetic parts added.

For N the out of the packet N gauge 'bag of farish axles' are either 15.0 or 15.7 mm axles - I can never remember which offhand, and will run very smoothly with the Parkside Dundas bearings (to the point bogies alone will trundle off down slight slopes on your desk)

For finescale the bigger problem is likely to be the terrier into 2mm fine scale standards as the wheels are force fit and once removed almost impossible to re-attach reliably