Finally hit the scales

My calculations:

Trailer and hitch weigh 8330 lbs (16060 - 7680)

Correct, assuming WDH was left attached to TT and not in/on truck when Truck Alone weights were measured.

Trailer without WD takes 440 lbs from steering wheels, WD puts 200 lbs back. Front axle load restoration about 49%. From what I understand, Ford recommends 50% FALR.

Correct.

Trailer without WD adds 1620 lbs to rear axle, WD puts 320 back on trailer.

Correct on the 1620 added to rear. WD put 320 back on TV rear axle -- not on trailer

Tongue weight 1300 lbs and hitch redistributes 520 lbs.

Indicated tongue weight is (3800+5060)-7680 = 1180#. WD removed 320# from rear axle with 200# added to front and 120# added to TT.

All of your axle load values look very good -- nearly a "text book" data set.

I am confused. I used a tongue weight scale in the driveway. It showed 1000 lbs tongue weight. While filling fresh (located behind axles) tank, I watched it drop to 800 lbs. Maybe tongue weight scale is wrong?

I assume the WDH was not attached to the TT when you used the Sherline. If so, your driveway tongue weight and the scales tongue weight would differ at least by the weight of the WDH.
Filling a water tank would not cause tongue weight to drop by 200#. I would guess a problem with the sherline.

It's good to see height data reported

along with load data.
For your rear axle, there is a good corellation between load and height.

However for the front axle, the correleation is not good. Perhaps the 41 3/4 and the 41 1/2 got reversed?
OTOH, it is not uncommon for fender height and axle load data to show a poor correlation.

Ron