I've got a 1951 3100 and it has a large (about 9") round speaker mounted on the center hump of the firewall, below the dash. I have not seen any such animal in the options or accessories but seem to remember seeing something about a "dash speaker" on earlier trucks from the '30s. This sure looks factory installed, nicely snugged-up against the sound batt. Does anybody have any information about this thing??
