Silver Pocket Knife - help me identify mark, Please!

[collectorama]

I have a silver pocket knife with a marking on the lower knife blade I need help identifying. It is an uppercase "R" then I think a cursive "D" followed by an uppercase "P". Thank you for your help!

[silverly]

Welcome to the forum. Great looking fruit knife. I'm afraid I can't help with its origin, but I kind of doubt it is American. However, I look forward to learning better.