Flanges - It looks to me like like the flanges are around an inch long, our rookie year, we used 1" flanges and thought it was overkill, this year we're using 0.75" flanges. Like what Stogi said, we use two basic flange sizes, 0.75 and 0.500. This just makes the brake operator's life a lot easier, and it looks like you've done that.
Gearboxes - I'll say that using flanges to make the sides of the gearboxes is a lot harder. I have no doubt that our shop and your shop can make those flanges the right size, it just seems to me using bolts and spacer/standoffs is a lot easier.
@Stogi, while yes, it would be better to use standard punches, their shop may just have waterjet or laser cutting. You can punch those lightening patterns out if you had indexable tools. One of our sponsor's shops has a punch and we even designed our parts so it can be punched out by them but they ended up throwing it on their laser since it was so much easier for them to nest it and just throw it on and cut, not worrying about what tooling they had in the punch and tool paths or anything.
Overall, it looks like excellent work. It looks like that gearbox shaft isn't supported by a bearing but I'm sure you'll fix that
