What is this cigar cutter? I can't identify it?

In my parents estate I came accross an unusual cigar cutter. It is made of a horn, has sterling ends and the cutter is embedded within the bone (not stuck on the ends). There is a small marking on it that looks like an arm and hammer having an H in the middle. It also says Sterling with the numbers 418 after. I searched the web and did not find anyhting close. Has anyone seen one like this?

Thanks for any leads.

Mike