Trying to find out Regiment

These are photos of my Grandfather (top right in squad photo and middle of photo with 4 people)
Really would like to try and find out what regiment he was in but unsure of how to tell. He lived in Gloucestershire (Woodmancote) when WW2 started. My mum thinks he went to Malta and Gibraltar. Any help or advice would be great.

There’s not much to go on.

The first photo suggests by the absence of cap badges on all but the NCO’s in the middle of the front row that it might be a basic training squad or others not assigned to a unit or corps.

If your grandfather is the man standing in the middle of the second photo, his uniform suggests he might be a mechanic or similar, as does the uniform of the man on his left (right of photo). Or maybe drivers. Or maybe any other troops who aren’t obviously infantry, artillery or armour. Or maybe any of the latter in a base camp. Who knows?

Assuming that the man on the left of the second photo is in the same unit as your grandfather, your best starting point would be to get an enhancement of his cap badge to see if it identifies a unit.

It would be much simpler to ignore all that and apply for his service record at if you have his name, date of birth and service number.