I have given some thought as to what I would consider must haves vs. would be nice to have.
Feel free to add your thoughts.
Must Haves (In addition to a basic set of hand tools with torque wrench)
Water proof ignition adapter set
8 sided axle nut wrench
1-1/2 socket for lug nuts (will have to be 3/4 drive but you can get an adapter to 1/2 drive
Multi-Meter
Vacuum Gauge.. (many will double as fuel pump pressure test)
Spark Plug tester light ($2.99 at Harbor Freight yes it will work on mil spec plugs if you use it backwards

Timing light 12v is ok you just have to have a power source
Jack and stands
Manual--Manuals--Manuals!!!!!!!!
Nice to haves:
Drag Link sockets (for drag links and brake drum screws)
Compression Tester
Leak Down Tester
Tachometer
Low Voltage test set
This list can get really long

If you are going to own a 50+ year old truck you have to have some support tools