Super Orbit is System 80A

Because it's 40 years old and likely deteriorated/contaminated to the point that it cannot hold a stable output voltage. Otherwise, if yours is working, then don't change it. These are only some established recommendations for improving operation and reliability.

Also, taking this board apart is a total pain in the ass. As per Pinwiki: "a good strategy is to replace all failure prone parts, whether the parts have failed or not, to avoid disassembling the power supply more than once."

For the same reason. It's a very cheap component that is prone to failure and separating this board from the heat-sink plate is a royal pain in the ass. Replace what you can when you have the chance.

Wattage rating is the MAXIMUM power the resistor can handle. When in doubt, go UP... never go down. If you need ½-watt then ½-watt is the MINIMUM you should use.

Where is it saying to use 1-watt? The circuit shows this pot in series with ¼-watt resistors R7 and R14, so if ¼-watt resistors can handle the branch current, then so will a ¼-watt potentiometer. Otherwise, the original R7 and R14 resistors would have burned up decades ago.

Screen Shot 2023-03-23 at 11.46.39 AM (resized).png

I replaced mine with this ¼-watt pot 2 years ago - no issues.

https://a.co/d/9v6dh7h

For this pot, 0-500 ohms is the range you need. If you can only find 0-750 ohms, that would work too. You can go up a little on the pot's resistance within reason. Example, if you use a 0-1,000 ohm, then only the first half of the number of screw-turns will be 0-500 ohms. If you use a 0-10,000 ohm, then the 0-500 ohms will be so low within the number of turns, adjusting it will be very difficult. Try to get something as close to 500 ohms as possible without going too far over. The closer you get to 500, the easier adjusting it will be.

Finally, the number of potentiometer turns. If you get a higher number of screw turns, then adjusting it for precise voltage will be much easier. More turns to achieve the same amount of change.