Hi jf42. Thanks for taking the time to write this up, I appreciate it.
Can you explain why you say he was a driver of company transport/or specialist role? He was born before 1890 and was 26 when he joined in 1913 according to his TA 4 years form so you are probably right about the fitness part. I'm not sure about the stripes, I thought they meant rank in the army? Also where it says "Have you ever served in the Army...? etc" it appears to say "1st Sussex RE." "Completion of Volunteer service", so that must be for the star you are mentioning.
His reg.no. was 1115 which matches with these lines in a document I found online.
00001_1115th Mechanical Transport Company Royal Army Service Corps
00001_1115th Motor Transport Company
00001_1115th Motor Transport Company Indian Marine Transport
00001_1115th Motor Transport Company Royal Army Service Corps
The second man is the Nephew of the first man, he was born in 1920 and we know he did something in WW2, my Grandma says he was a chef but I'm not sure if she is correct or not - I'm still trying to find out. Maybe he was Grenadier Guards or Fusilier regiment in WW2? If those existed during that period, that is.