Can’t wait to see the truck. If it’s been sitting for a while your going to need to do brakes. Rockauto has everything you’ll need for brakes but you’ll have to use 620 parts, mostly. They all work. Only trouble I had was that some wheel cylinders rubbed on the drums so you’ll need to replace them with a new ones too.
One thing I would focus on is the stopping power of the drum brakes on all four wheels. Power, carburetors, 5speeds are all good but these trucks have manually adjustable brakes that need to be maintenanced on a regular basis. Usually every oil change. When out of adjustment the truck will learch to the side with the most brake contact. We just get used to this unsafe thrill. For my kiddo I’d be looking at a front disc brake upgrade. Custom brackets, spindle/hub/caliper/rotor assy, steering linkage, proportioning valve and a couple new brake lines. Probably also some larger wheels with wide tires( once again braking + traction). This is well covered here.
Also seats with a high head rest, just in case of a hard rear end collision, because with the stock bench seat your head would bounce off or break the rear window.
Oh and just to be clear I’ve done none of that on my truck because I guess I dont care about my own safety.
Edit: Lap belt suck too. If it doesn’t have shoulder belts, install them