Hey, I've got one of those that's NOS also. It mounts to bottom lip of the dash. Mine was missing the key also. I made one from an old clock windup key. Notched it to fit over the tit on the shaft. There aren't too many of them out there anymore. The last NOS one I saw sold for $350. I believe they were used in the 30's to 40's. They look great inside trucks.
