TransTrem parts source?

Hello fellow Steinbergeristas,
As the title suggests, I am looking for a worn part for my 1988 GM4T transtrem, it's called the "transposing pin", i.e. the little stud the transtrem locks onto. On mine, the very fine little metal pin has corrode/worn to the point I can no longer lock in. I've already tried Headless and they have none of these parts... Does anyone have/know where I can find one of these?
Thanks!