Was the contact pattern run with a little resistance held onto the pinion flange? I usually grab the pinion flange tightly with a welding glove, and turn the ring gear back and forth vigorously with a box end wrench on one of the attaching bolts. It gives a much more distinct contact patch to evaluate.

That pattern looks pretty good, but it's easier to read with a little more load on the gears.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!