Steve,
also page 109 of David J. Baker's book "The Heyday of the Shotgun" shows a beautiful engraved 12 bore, full sidelock, hammerless O/U made by Frederick Beesley, London. It was called "The Shootover Gun" with a Patent date 1913 which makes it legit for use if their cut off date is 1914.
On the other hand, it may be by a majority vote that the club only wants SxS's used in their events and that is understandable.
Steve.......since Dangerous Dave sold out in Montegue. They new guy does not carry those European primers that your brass uses and I can find no source for them currently. You might consider investing some money in the brass Midway sells at about $22.00 a box. I bought $140.00 worth last year because the price of brass keeps going up. I paid $18 a box for them last year and they may be more than $22 a box of 25 by now.
Don't feel bad about shooting them as I just loaded 50 new ones with Pyrodex and 1-1/4 oz. of #6's for upland hunts and I have another 50 that I'll be loaded with 1-3/8 oz. of #3 lead for turkey hunts. I have two 25# bags left of #3 lead and need to load it up for something, Coyote's, fox, turkeys, etc.
I also have 3 boxes of new brass 20 ga. 2-1/2" that are primed and ready to load with Pyrodex and 1 oz. of 7-1/2's. Midway has a good selection of brass 2-1/2" shells now, in 12, 16, 20, 24, 28 & 410. I don't see why they don't get them made in 10 ga. 2-7/8". I think they are missing the boat on that gauge. All this new brass they have uses large pictol primers just like the old ones did.
And BTW those British tweed caps don't look any worse than that "Butt Ugly" old crushed straw coboy hat you wear on the Sage Hen hunts. It's a wonder the F&W Officers don't write you a ticket for "Hunting Ugly" Bwahahahaha!!!
Let me know if you need any of these BP loads I just made?
Dave