my '46 has a hole with no thumb bolt [probably went missing somewhere in it's long career as a truck] but is connected to the lock down inside and I just assumed that this was how one locks the drivers' side door ..... the thumb piece is available from fillingstation.com on p. 16 of their October catalog which is available online. Seeing this part gives an idea of how the door was locked on these models [from the inside that is] .....
don't know anything else but am sure plenty of stovebolters can confirm or dis-confirm this
lane
