Trying to identify antique thimble holder markings?

[anneten]

I inherited this silverplated thimble case with the markings "HG" and below it what appears to be an image of a "Key" and the letter "W." Also, inside the holder and the lid are three "slashes" and an "X". I have searched this site and others and can't find anything like it. Does someone know these markings? Or the country of origin? Or where else I might look? I would appreciate any help you can give!