The pop rivets didn't bother me, actually I used solid rivets, where I could, a lot more than the plans called for. I have experimented with several AOI, anywhere from 3 to 6 degrees. I have it pretty good now at 4.8. My biggest complaint is the nose gear and the design around the retract mechanism, as well as the shimmy. I mostly have the shimmy better, but still not eliminated. We have an exceptionally nice grass strip at Felts Field, so I opt for that when I can. I found that the pressed in bronze bearings crashed in the middle of the aluminum block used to hold the forks. That caused a .015 crown that held up the bearing surface. I turned it down on the lathe and it made it better.
Two major issues with the nose gear.
1: There is no way to seal the opening where the hydraulic lines go to the actuator cylinder, so if you do any displacement taxiing, water is forced up and into the compartments on either side of the nose gear well.
2: There is no down lock on the nose gear. The only thing that holds it in the down position is the hydraulic pressure in the cylinder. Since the cylinder is fully extended and virtually parallel to the gear leg, the geometry is so poor that the gear comes out of the full down position when you push the airplane backwards. Once you do that the wheels caster around and produce so much camber that they will no longer caster. Then you are screwed. If you have lots of big friends they can sit on the back of the floats and raise nose so the gear can go back into the full down position. What I have to do is use cargo straps between the nose gear and the step to hold the gear in the full down position. I don't know why they changed the design between the 1800's and the 2200's but they should have left it the way it was. The Zenith guys have been unresponsive to these issues.
I can post pictures if anyone is interested. I sent some to Zenith, but as I said, unresponsive.
If I had it to do over, I would not build these floats.