just got a 83 MT racing frame and it has a Odyssey pozi-stop seat post clamp. not sure what it is? has some kind of tab hanging from it. anyone?

The Pozi-Stop was a seat post clamp with a cable router, designed (and initially marketed) by Steve Veltman, that worked with Odyssey Pitbull brakes. Try the mid-school forum, they'll tell you what you need to know.

I have one of those sitting on my old race frame with pit bulls and VG center piece, collecting dust.

thats why i couldnt figure it out i'm missing the arm. thanks.