Schrader gauge question

[29tudorsedan]

I picked one of these gauges up working for $6 along with the leather pouch, and a tire at 35 psi was reading 20 on the gauge, I oiled the numbered shaft and it read perfectly for a short while and I can only guess what was left of the gasket on the inside disintegrated from the oil after it wicked up the shaft with a few uses because it just extends fully and leaks air now.

Does anyone have any experience with these? Are they repairable?

Removing the head from it I'm met with a red disc with a hole in the center, and I'm not sure if there is much I can disassemble from there.

What I'm thinking of if I can't get it apart is walking an o-ring up the shaft and hopefully it will seat somewhere farther up and stop the leak.

I don't have much in it, so if it can be fixed I'd give it a shot.

Thanks