I am not sure when they stopped numbering them. At least some of the jhv 41's had numbered rods. I don't know whether it ended during jhv41 or if it extended into the jhv 42 production. It is hard to find any world war 2 Kar.98k or G.98/40 with a matching numbered rod.
Note that simply finding a loose E/56 marked cleaning rod is an accomplishment.