Any question answered...

Ta. Think this will be the way I'll end up going. I thought I must be missing something. Figured there'd be loads of train/traction engine/model beardy enthusiast sorts out there creating a reasonable market for this sort of thing.

if it was me and I had access to the orginal/someone that does I'd make one by getting epoxy paste to make a mould, then melt down something like pewter to cast it with. Not brass but dirt cheap and eminently doable on your stove very quickly and if you paint it you'd not know.