Jeff, I've got a jack very similar to yours. I got mine from my Dad, who got it from his dad, who supposably brought it home from the rail road. :confused: Unfortunately, I don't have the opportunity to verify this with my granddad. I'll have to check mine more closely for any numbers. The handle is long gone, so I can't help with the GM logo there. Just a few weeks ago, I saw a jack of identical design, just 3 times bigger, in an antique store in Franklin, N.C. The tag claimed it was from a Mack truck. Believable? Anybody's guess.
