Illustrative collection of live action target and live bird shooting from the 30s-60s
http://www.trapshooters.com/threads/vintage-live-action-trap-and-live-bird-shooting.514889/ The problem with still photos is that the shooters are almost always in the 'ready position' with the head off the stock.
Not sure why there are 2 gentlemen, 2 yards apart, as I have not come across any reports of "head-to-head" or 2 man pigeon competitions at Monte Carlo. Note the far shooter is wearing a glove on his forward hand.
Not enough resolution to say, but the near shooting sure looks to be using a Parker Trojan?? I had one 12g once with 2 1/2" chambers and British proofmarks
More images from Monte Carlo here
http://www.picturetrail.com/sfx/album/view/24800261 
