Hi Ariel
I'm somewhat alarmed to see the lock ring for the wheel that is not a complete circle. Is that the way it was made or has it been cut for removal? I can't tell from the photo. If it has been cut through DO NOT TRY AND REPAIR IT, scrap it and get a replacement. If it was made that way then it is not an original CCKW component. These things can be lethal and have certainly killed people due to faults or lack of knowledge so please be careful and take no chances.
I wish you every success with your restoration. It looks like you are off to a good start and I will be interested to follow it through to completion.
Hi David, that ring of the rim is not original GMC, is used by the 1957 Chevrolet truck and Ford 600. They work well, but try to get the original, is difficult. I appreciate your interest, welcome advice. regards