Hmmm ... I take back what I said, it's not a 106 RCL, its a 120 mm L2A2 WOMBAT (The BAT was the L2A1). Both used the spotting rifle, but only the BAT had the muzzle towing attachment, the remains of which is visible on the WOMBAT. The rounds are in an angled rack in the back of the vehicle, and the WOMBAT is demounted behind. Unlike the Aust Gunbuggy, which had a 270 degree arc of fire, the Brit WOMBAT could only be fired from the vehicle over a very short arc centred on 90 degrees to the chassis line.
I've just received Pat Ware's book 'Military Land Rover' by Haynes Publishing. Some pretty woeful captions about the Aust images, but a few of the WOMBAT in Brit Land Rovers made me realise my error in the earlier post.
Mike