Not reviewing all you have done just going to rattle off all the stuff I would make sure was done before undertaking such a journey.
Complete cooling system check-up. New thermostat and all hoses. New belt. At minimum flush and pressure test radiator (or go new). Install a new water pump. They are cheap and you'll know its good for the trip. If using an OEM clutch fan be sure to check it too. If electric and age unknown, I'd put a new one on. Carry a spare relay and terminals too. High draw stuff can wreak havoc on loose connections, etc. Be prepared.
Ignition system. If old school, replace points, condenser, cap and rotor. New plugs and wires. Coils are fairly cheap, bring a back-up. If something modern, like a Pertronix dizzy, carry an spare module. Inspect the coil and dizzy wiring and repair anything questionable. Install new and carry back-up apron starter solenoid.
Charging system. New alternator (or carry a spare). New belt. Check wiring and repair as needed.
Fuel system. New mech pump if so equipped. I always carry a back-up electric pump. New under hood fuel hoses. New filter. Carry a spare filter or two as well. New air filter. Carb? If you don't rebuild beforehand it carry a kit to do so.
Brakes. Inspect, clean and replace parts as needed. Inspect all old hard and soft brake lines for damage and wear. Replace/repair as needed. Top off fluid.
Chassis. New front wheel bearings (or at least take them out and repack with grease). Inspect and grease/replace u-joints. Service diff or at minimum verify gear lube level. Inspect and verify torque on EVERYTHING.
What I pack and take along on long trips.
Tool kit. I have the bare minimum but enough to handle just about anything. Wrenches, Crescent wrench, screwdrivers, a few select sockets to replace possible parts like an alternator, etc. Any specialty tool I know something on my car requires (Allen wrenches, for example) Tire pressure gauge. Wiring tools like cutters, crimper/stripper, electrical tape and some wire and terminals. Tube of RTV. Flashlight.
Spare Parts. I carry the following; in-tank electric fuel pump and sock (gasket), belts, relays, starter solenoid, ignition switch, headlight switch, fuses, gasket material, a spark plug and a couple long plug wires. Various lengths of a few gauges of wire. Electrical tape and zip ties.
