I just saw this thread (was away from the PC's when it was running)
I didn't use a VW wiper unit, as I had ordered one from CMC which never got delivered (Boy! was I ever surprised at THAT!)
Once in receivership, CMC eventually sent me a wiper system from Specialty Auto Windows which, after a certain amount of easy custom mounting, fits and works nicely.
The motor mounts up over the passenger's feet behind the dash which can't be seen, but I needed to fabricate a custom mount to attach it to the frame crossmember behind the dash. The wipers are moved by a coiled spring inside of an aluminum tube which is pushed back and forth by the motor. Each wiper has a gear which engages the coiled spring as it slides back and forth.
Everything is variable: distance between wiper posts, start and stop positions of wipers, length of stroke, etc. You can even have the wipers go up and down like a bird's wings, flapping up in the center or up on the sides!
The system is two-speed, and the switch has a push-action for a washer motor. The hardest part of the installation was adapting the Porsche/VW dash knob to the Specialty dash switch.
Used them in mist through downpour and they work great.
I know you've already gone to a '69 VW unit, but I thought others might benefit from this....