I know the frame production number does not match the serial number on cubs. Some years ago I remember seeing something here that referenced the production number to the serial number.... I know someone here has that information. Heres the story: my father in law is an old time Ak pilot that flew for everybody from Reeve to Sheldon. Retired to Az. He flew until he was well into his 80's, but he is 90ish now, and among other things, his memory is not so good. anyway.... he has a cub project in the garage that he meant to build but never will. He didn't get the logs with the project, they were supposed to be sent or something. now its 10 years later and no logs, and.... he can't remember where or who he got the cub from. obviously, if I had the S/N, I could locate the registered owner and try to retrieve the stuff. His family would like to sell the thing to help pay for his care. I'm the only one in the family with aircraft experience, so they asked me how to deal with it. thanks