How do you adjust headlight travel on my GT4?

1975 308 GT4
I've read all of the threads on adjustment, and still can't get a definitive (or working) answer. One of my headlights parks higher than the other when down. Should be a simple adjustment right?

Things I've done:
- Detached the pivot arm and changed its position. When I do this, the light will go down further, but the motor pulls it back up so it parks in the same position. In other words, it dips down briefly then is back to where I don't want it.
- Adjusted both the upper and lower stop screws. I have moved these completely out of the way and the light will still park in the same place. It stops long before it reaches the stop screw.
- Made tiny adjustments via the manual headlight dials on the motors hoping it might make a difference - it did not.
- Unbolted the entire headlight assembly mount to check to see if it was installed too high or too far back, which might make the headlight cover stand proud - no luck.

I'm at a loss. Anybody have any experience with this? I must be doing something wrong. Thanks - Matt

 

It's just the leading edge. Sits too high by about 1 cm at the front.