World War I Sniper Rifle !

Here we have a Jeffery .475 Number 2 double rifle with the British "Broad Arrow" stamp, which would indicate that she was purchased through the War Office. British snipers used these large caliber rifles to engage German snipers who used heavy steel plates for protecting their firing loop holes.

Has any one seen these markings on any other double rifles? my knowledge in this area is limited to what I have read from Maj. Hesketh-Prichard's "Sniping in France" and Ian Skennerton's "The British Sniper."

I believe some one has the sales records for W J Jeffery, I would like the contact information for him if any one has it, thanks.

John