If you're talking about a DL50, the only ones with serial numbers were ones sold by Bob Kramer of DLUSA, they were hand engraved by himwith an electric pencil engraver. The case and cylinderwere numbered,I've seen them on the front, or back, I've even seen some with different numbers on the case than are on the cylinder. Bob labeled the 100s he sold as well.

The DLE30s, 55s and 111s are all serialized at the DLE factory and allon the back of the crankcase only.