That all looks really nice. A syringe is a game changer but that mixing gun is even better. I'm probably going to break down and buy one for my wing ribs, since I'll have no difficulty using up an entire set of tubes.
Nice save on riveting that push-pull tube. I think I was in a near panic when I mixed my first few batches of Hysol. I've gotten better about making sure everything is absolutely ready before mixing, and I've also learned that I don't need to be in that big of a hurry with it.