Update
- The reason the potentiometer base doesn't fit well is because of the pin shapes. They're metal strips that measure 1.05mm wide and .29mm thick at the breadboard end, but this thin shaft is only 3.9mm long at which point the width broadens to 1.98mm. I do not have a tool to measure the breadboard holes; that wider shaft doesn't fit in the hole but the length of thin shaft isn't long enough to make contact unless you push it down hard.
Presumably I need to solder header pins onto the ends to make it work as intended. I don't have the first clue about soldering, anyone throw me a bone?