Welcome to vwar!
Is there any particular reason you feel the transmission needs a rebuild? Unless there is some sort of specific trouble you are having I say no reason to rebuild it. The main reason I say that is that most on here will agree the autostick transmission is virtually bulletproof. The immediate "on-off" of the internal clutch with no slipping, plus the far less frequent shifting, means it wears WAAAYY slower than a conventional 4 speed clutch. Grinding gears, etc in the autostick system are usually a result of the clutch arm being out of adjustment or the clutch servo not working properly- NOT something internal to the transmission.
My family has owned my 69 autostick since it was new and both me and my two sisters learned to drive on it and I ragged it out (as much as you can do that to a bug) in high school. The autostick didn't miss a beat through all that- we only replaced it 5-6 years ago when the clutch had gotten worn enough to where it wouldn't hold against the pressure plate any longer. That's 40 years with the same transmission

The only thing I would recommend is draining the old gear oil out and replacing with new oil and a new pan gasket. vwnos has good German Goetz pan gaskets for only $5 + low shipping cost, a fantastic deal:
https://www.vwnos.com/001-301-139-aRegarding the gear oil, make sure it is STRAIGHT GL-4. There are whispers that the new GL-5 spec gear oil will damage the softer brass synchros in these older cars. GL-4 can be tough to find, but Napa sells Sta-Lube 85W-90 GL-4 gear oil for a decent price that should be fine.
Other than that I say leave it and put the $800 toward other parts of the car and enjoy driving it once it's back together! I'd estimate a good long while before you have to worry about the autostick.