Good Evening Wally
Thanks again for your very informative reply.
Sadly, the M20 had been re-registered before my Uncle acquired it so unfortunately he's no idea what it's military 'registration' was.
I'd forgotten to mention one other piece of information that was found during the disassembly. A plate was found bearing the words 'Rebuilt & Serviced 1945'. I not sure if this is of huge importance but that's why I'm asking you & the other good people of this forum for help. I'm, well, clueless basically! Ask me about Technic Lego I'm possibly your man, ask me about anything beyond basic engineering ect...!
I know I must sound like the proverbial 'scratched record' but if you have any idea as to how the M20's military number might be discovered myself and my Uncle would be most grateful.
My gratitude and regards.
grum64