Here's a Sachs freewheel on the local Craigslist.

Sachs Maillard 6 speed Freewheel---New Old Stock - $30 (NE Eugene)

6 spd:
13-15-17-21-26-32



You don't quite get the 34 you wanted, but it is pretty big.

I could probably snag it and drop it in the mail, if the seller isn't wanting to ship.