I grew up with a '46 1-Ton pickup. The finger lever on the shifter is the reverse lockout. Lifting it will allow you to go into reverse, which is to the left, and down (next to 2nd).
The funky screws are called clutch head screws, and there are a number of other threads on here about those, and where to get screwdrivers for them.
Good luck with your project!!
