Stuart,
2nd Regiment Royal Canadian Artillery (2RCHA) belongs to 2 Brigade out of Petawawa. 2RCHA is part of the Royal Regiment of Canadian Artillery - The Royal Canadian Regiment is an infantry Regiment with three batallions and thus their tac symbol would have been an "X" as opposed to the "ball".The tac symbol is correct for 2RCHA although the mech symbol (O) seems a little large for the tac sign. Some gunner got creative perhaps...
2RCHA was the first unit to receive the iltis and deployed to Ex RV85 with the wee-beasties. An interesting note - we had a battery from the Royal Australian Artillery attached to 2RCHA for RV85. They drove back from Suffield Alberta (my present location) to Petawawa in an iltis convoy, taking in the beauty of the land.
So, your iltis in the photo may have been one of the first employed in the Canadian Army.