Most of the old Chevy truck vendors carry some sort of universal rubber floor mat material you can use to make a mat for the '37. I strongly recommend you make a template as suggested by 37 GC, so that you make mistakes on your disposable template material and not on the expensive rubber mat itself. I would try heavy paper, like painters use to mask windows, as it is easier to cut than cardboard, and if you trim too much you can tape extra on the template to remove your mistake.
When cutting holes I also recommend you invest in a hole punch set, which is invaluable for other things like cutting your own gaskets. For example, the hole for the headlight dimmer switch, hole for accelerator rod, etc. I also use a punch at the ends of the slots for pedals and handbrake. The rounded contour at the ends of these slots help prevent rips or stress cracks over time in the floor mat material.
As opposed to the art deco trucks and Advance Design trucks, my '37 has no anchors for the floor mat, but mine has stayed in place because there are enough structures holding it (pedals, steering column, tranny and hand brake hole, etc). I removed the stick shift on my truck to get it out of the way, easy to do with the 4 spd shifter which takes seconds to remove. I cut a verticle slit above the steering column and connected the steering column hole with the pedal slots. I also made a vertical slit for the wire harness and speedometer cable that exits the cab through the floor board. These slits obviously allow you to install the mat without disassembling your truck! After successfully transferring the pattern to the rubber mat, I put foil backed temp and sound deadener on the back of the mat, bonded with spray adhesive.
I hope the above information helps,
Last edited by Lightholder's Dad; Sun Jun 21 2020 05:41 PM. Reason: clarity