Thanks for looking in dickr.
The steel tires are shrink fitted to the wheels and the wheels are permanently locktited to the axles.
It is an English design at what they call 5 in guage and it is a freelance design, (not a model of any particular loco), by Martin Evans, who was editor of Model Engineer magazine in England in the 60s and maybe into the 70s.
I have grand designs of making the boiler myself but you know what they say about "the best laid plans of mice and men". LOL
Ron