it's a 12mm fine thread - 1.5 or 1.75
That was very much considered as well!I stripped mine before I knew it was plastic. The replacement nut on this here is not e exactly the same but works fine. You'll have to pull off the handle with some pliers.
His was 15$ but I believe he crafted it himself. It's got a bit extra threadage for added support. Overall, I'm stoked, fits very well.I believe 01-7700 makes replacement plastic nuts for less than the Mikuni plunger.