From someone else's page on facebook where the rifle was also discussed:

Ajay Raj Singh Chauhan

Just shared this picture with the present HH of Balrampur, he said he only sold this gun in early eighties when the ruling came of owning only three weapons on one license. He had to give away about 50-60 rifles and some of them were presentations from Queen Victoria and her husband Prince Albert. Does any one have any idea who owns this weapon now ?