Dan A Tracer Card is a '6 x 4' file card which contains the soldiers basic details such as his Army Service Number, the date he signed up, the units and Regiments posted to with dates, details of any periods in Hospitals and anything post War such as the date when transferred out and/or to the Army Reserve. The Tracer Cards used to be held by the MOD but were sent out to various Museums a number of years ago. All of the Royal Armoured Corps Tracer Cards are now at the Bovington Tank Museum. The only details I have of John are: 7957266 (his Army Service Number) Trooper G.J.Webster 'HQ' Squadron. That information will be enough for Bovington to locate his Tracer Card. I suggest you phone them, ask for the 'Museum Library' and you will then find them extremely helpful. In the case of my fathers Card, it's the best £5 I've ever spent! I've checked my copy of 'None Had Lances' and John is not mentioned by name (which is not that surprising, but it will includes lots of information about HQ Squadron).