Quoted:
Here's my take.
I personally prefer to modernize the safety features and aspects of older vehicles. By that I mean gut the electrical and re-wire EVERYTHING, all that old wiring is a fire hazard IMHO. This also gets rid of any potential issues with grounds being shoddy at best causing all sorts of weird electrical gremlins. If you get an OEM repo or an aftermarket blades style it's up to you, doesn't really matter so long as the wires are new and run properly (I go with universal blade style kits).
Next I'll at the very minimum install a 2 pot brake master so I can divide the front and rear brakes just because I don't want 1 leak resulting in me not being able to stop. Preferably I'd also upgrade the front brakes to disc brakes for better stopping power. Sure drums will do the job, but I'd rather stop sooner than crash into some asshat who pulls out in front of me. Probably want to see what CPP has for your truck, you didn't mention make or model so I can't give any better recommendation than that.
Since you'll have the front end torn down to do all of the above and you'll have to get an alignment you might as well do springs/shocks, ball joints, and steering linkages. Good chance those old springs are sagging now causing a not so great ride.
After that new fluids, driveshaft carrier bearing (good chance it'll be shot too), and inspect the u-joints and clips as well as the exhaust for rust damage while you're under there.
Beyond that everything else is gravy on the cake to me. And you don't need no damn AC if you've got vent windows and scoop vents. Those things work great at diverting a lot of air into the cab.
Now with all of that said and done....If I were to come into posession of a 1950's Chevy stepside truck that wasn't quite worth fully restoring I'd be doing a S10 frame swap with a small static drop and a 383 stroker/5 spd combo, and I'd be putting in a classic air AC system and maybe even cruise control (even if it was just a throttle cable, old school cruise control). Everything else though would probably remain normalish
The truck is going to get a full rebuild. Wiring is serious business, so that will be gutted and redone with modern components.
Minimum will be a dual master, and depending on the condition of the drums likely go to 4-wheel disc. A newer rear end with disc brakes bolts in, and there's one company that actually makes a disc brake conversion for this truck (International) that I'd probably use. Front leafs need to be re-arched at a minimum. Rears might be OK still. New shocks all around, probably Bilsteins if possible. It doesn't have modern-style ball joints really, but I think parts are available to rebuild the originals. If the steering box is too far gone, that may be an issue. Apparently Toyota power units are potential upgrades.
Wife was surprised to hear it didn't come with seat belts, so those will be going in.
The truck will never likely be a daily driver. Errands that require a truck and for fun, mostly.
ETA: will probably be installing a newer steering column (not a tilt column) with a collapsible shaft at least. The steering box is in front of the axle, and has a one-piece steering shaft from horn to steering box that makes me a little nervous. Learning about "flail chest" in our first responder certification didn't help, either.