Yep, you usually only got an exterior mirror mounted to the driver's side door hinge on these trucks. Many have had interior rearview mirrors added to them, but you can't really see all that much through them. Pass. side exterior mirror is a very rare option to find. Repros are made, but the quality is... well, typical of most reproduction parts.
Is the wheel a split rim, or does it look like a regular old 6-bolt wheel from '39-'48 other than the 8 spyder deal? '37-'38 car and 1/2-ton pickup wheels are 6-bolt, 16" and have the 8 spyder centers. The 3/4-tons used 6-bolt wheels from '37 up until '46 when they went to 8-bolt, so '37-'38 wheels would fit a '39 3/4-ton.
Is this one of the trucks that was on ebay recently?