I also have been trying to find the right radio for '41 pick up and have established the folowing:
1) Brown faced "thumb wheel controlled" radios were offered as accessory items for '42-46 trucks..they mounted under the dash to the left of the wheel.
2) ? to '41 radios were also accessory items...they had a chrome on pot metal face and regular(twist)adjusting dials on either side of the radio.
