If you have the R-series key you want to have duplicated I’d try a real lock & key shop (ie, not a hardware store or WallyWorld).
I’ve had good luck getting obscure keys duplicated at lock & key shops, including having some made for which I didn’t have the key – I’ve had some cabinet lock keys made for which I knew only that it was a HON cabinet, lock numbered HN557 or etc.
A real lock and key shop has the ability to cut keys knowing only the number stamped on the lock, without having the actual key on hand to duplicate.