He was in the Royal Air Force. He does not come up on Forces War Records (doesn't surprise me, and his full record wouldn't be there anyway as it was WW2) which is the only site that gives a search against a service number as far as I am aware.
Unless you can find his NOK or establish that he has been died over 25 years then, as you are unrelated, you won't be able to apply for his service record as you probably know. The hope must be that someone recognises his name. Does any of the memorabilia have an indication as to his squadron, there may be an old comrades association?
maxD