Thanks Darling

(and everyone else for the comments).
I didn't take any before pictures but here is a shot from eBay of what the train started life looking like. It looks to be a near copy of the Goldlok trains available most places but quite difficult to find in the UK. The truck couplings are slightly different but I don't have any Goldlok track to be sure about how compatible that is.

I have this set too, which has no points and one less truck but the track and truck couplings are compatible. I'll post some more pics on the blog of the second train when I have time. That one I'm going to do as a straight unarmoured train I think.

I have some Goldlok trucks too, whcih have different couplings but can still be joined together with the other type.