Sounds like your tranny guy is doing a good job for you. Plus you are saving yourself a TON of money for your trouble, Bro.
As for the straight vs. angle cut gears, I don't know how accurate that quote I posted from the Off-Road forum is. It "sounds" reasonable and maybe certain years (earlier models) of the TH475 did have the straight cuts. However, it is not uncommon for a manufacturer to make changes to a product like that but not publicize those changes.
It is also very possible that the tranny is not the original and a previous owner swapped in a more common (and cheaper) TH400 at some point in the past.
1995 Coachmen Santara 360MB 36' w/slide.
Ford F53/460 chassis, 1997 Jeep Grand Cherokee "toad"