I think that getting the axles vertical to adjust the bearing preload (first) and the pinion backlash (second) is the key thing here. You'll want to get the preload set up WITHOUT having the pinion in place. Once the pinion is in place, you won't be able to get a good feel as the carrier/ring gear rotates. Doing that with all the gaskets on one side simplifies that task. Once the pinion is assembled into the banjo casting, you'll be swapping gaskets from one side to the other to get the backlash. Make sense? Here are some pix I took of my setup. I was lucky enough to come up with the plumber's vise...
PS: Looked up your location on maps.live and it looks like there are two chapters both with mailing addresses about an hour away from you. They must have members strung out along the coast possibly closer to you than you'd think?