Note that they each wear different markings, one just plain silver, one with the code letter Z, and the third, most interesting of all, seems to be in camouflage and wearing light blue roundels.
Is that's the case, then I would guess this is later than 1941. And I'd think this one has probably been to Fiji where the Vincents served operationally with No. 4 and No. 5 Squadrons. So this may be as late as 1943.