Good evening,
NCO's chevrons were worn on both sleeves of service dress and greatcoats. On battledress and shirts on right arm only in my time as per dress regs 1950. I am not sure whether that goes for dress regs 1934 as well which is what they would come under.
The 2nd photo shows more army personnel than RAF, another corporal on left of photo and all the men in back row. The chap holding the brides hand has a flash on his upper arm with lettering but unable to read it.
John915