Thiswould be better. The "universal" type wiring harnesses are basically all the same quality wire and use a prewired fuse box. They are just fine for you. This one is cheaper and has more extras. Free ship.
A 12 circuit harness for a stock, or near stock, 1950 truck will have extra circuits/wires.
The circuits on this harness are:
1. Wipers
2. Fan3 AC/heat
4. Gauges
5. Turn signal6. Choke7. Coil
8. Radio9. Horn
10. Headlights
11. Brake
12. HazardSo
Red circuits could be potential extras. There will be some ammeter, generator/alternator, subtle changes ....to be made for an older truck. No big deal. I suppose you are talking 12V conversion?