This suggestion may help or may hinder. Are the stones real Cairngorms(smoky quartz)? Any knowledgeable jeweler could tell you almost at a glance whether you have glass or real stones. Ok, it may not be of a quality to warrant real stones anyway even if it was made in the UK, but an avenue to have a brief look down? One thing for sure, if the stones are real, the dirk will not have come from India or China as a repro.