Yep Steve, any '37-'40 pickup carrier is hard to find, and yours for the 17" tire may be even more so. I think usually the slide out carrier got pitched behind the barn the first time the owner had to lay in the mud and wrestle the spare out. Then the spare lived in the pickup box or was mounted to the side of the box using some fence posts and a torch. If the rear fender had to be clearanced with a sledge hammer for the spare to fit, so be it.
I'm sure you can make something that will work just fine and watch for an original in the meantime. Do you have a Chevrolet Master Parts Catalog that has drawings of what the slide out carriers look like?
