I cleaned and lubed my spare door latch assembly and installed it. It looked like the handle spring is crimped in place and my original unit had some wear on the striking surfaces, It is a real pleasure to close the door without having to cock the inside handle, and it shuts smoother now. I removed the rear door lock cylinder to compare it and it too does not have the flat part. The rear door key cylinder shaft measures 1 3/4" while the passenger door key cylinder shaft measures 2". Picture attached, also a picture of the damage to the passenger cylinder. I removed the cylinder and it looks like that will need to be replaced. The 1929-1954 Chevrolet Master Parts and Accessories Catalog pg. 546 has a nice picture that shows the Cylinder as section 10.550 and that section lists it as GM part number 1394993 for 1941 to 1948. I'll guess they went to the flat blade shaft in '49? I did find one listing for that part but the cost is close to an aftermarket assembly. I also found a listing for a Briggs & Stratton part number 85319 door lock and keys for 1941 - 1947 sedan delivery that looks similar(probably different shaft) at triple the price. I haven't found a cross reference for Briggs & Stratton part numbers, does anyone know where I could find that? I contacted someone local about a used key cylinder, waiting to hear back. I also stopped by a locksmith, but that one couldn't help me. I may attempt to swap the cylinder guts myself if I can't find a locksmith for a reasonable rate.
