Despatch rider's early canvas helmet

As ever with this sort of question nothing is impossible.
The evidence for Great Britain and NW Europe is that Commonwealth despatch riders wore the Fibre or round Steel Helmets. There are references for this in the D-Day photographs. A contemporary film example is the first few minutes of "The Life and Death of Colonel Blimp" which shows real Despatch Riders from 1942.
For Italy and North Africa the older canvas helmets are more possible. You see riders with the ordinary MkII helmets which are not practical at high speed riding so they may have retained the canvas helmet as well.