They’re probably AFV helmets, which were virtually identical to the para ones anyway, except for the more complicated straps on the parachute one. The para ones usually ( but not always) had the scrim cover too. Dispatch riders (Don R’s) had similar helmets. http://www.militarytrader.com/military-trader-news/british_wwii_helmets_airborne_dispatch_rider_and_tank_crews
Was the 22nd Royal infantry or serving as a recce battalion?