Many thanks for the information and your thoughts MMowiec. I agree that the house is probably the original HQ of the company.
The token is of crown size and came in a red commemarative box(possibly not originally for the token?). I also thought it could have been something given away with the series of books but due to the success of the books I'd have thought a few more would still be popping up on the second hand market.
Anyway, it is an interesting find and I shall update here if I do find more information in the future.
Thanks again for your time and input.