My mother-in-law has these. She said they are old but not sure quiet how old. They both have the numbers 4218 engraved in them, also they both have WKC and groent? groden?or maybe groejen on one side of an x and looks like thaly? on the other side and Germany underneath the x.WKC is at the top with the K in center and W,C on the sides of an enlarged K. Any ideas on this, age? value?