Came accross a similar double Hammer with top lever. Marked Walsh Lovett and Co. No markings to determine the bore. Underside of the barrels is stamped Henrys Rifling A&T. Engraved with a Lion on the right and a Tiger on the left side. From the thickness of the chambers i think its a 500BPE but the owner claims to have fired 500NE ammunition. All parts except the wood appear original, the bore is good.