As far as serving in WWI is concerned, there are medal index cards for 6 soldiers named George Haines, who served in one of the branches of the Royal Artillery [17 if you add those with second names]. A quick way to confirm if he’s one would be if you have a photograph of him in his uniform cWWII, if he has medal ribbons chances are they’re probably from WWI.

As far as ANY records are concerned, as he served in the 1920’s and WWII, they will still be with the MoD. Although it appears to be possible to obtain copies without a service number, the chances are reduced and there will be a charge whether successful or not. You need to complete SAR and kinship forms and provide proof of death [copy of certificate], see http://www.veterans-uk.info/ for full details.

Jeff