Capt Geoffrey E. Lewis-Pembroke Yeomanry-Need Help

I'm trying to do some research on Captain Geoffrey E. Lewis who served in the Pembroke Yeomanry during WWII. Does anyone have some good sources I could reach out to or use? I'm trying to find out which regiment he served in (102nd or 146th, both of which are Royal Artillery) as well more overall details on his wartime service (time of service, campaigns participated in, medals received, etc.). Just going off of the two regiments he could have served in he probably participated in at least the North African and Italian campaigns, maybe even France if he was with the 146th. I've got his uniform coming in the mail, will post pics of it in the appropriate forum when it arrives. So far basic Googles searches haven't turned up anything. A search of The Gazette turned up an officer of the same name but he served in a different Welsh unit and it was during WWI. Any help would be appreciated!