My Kitfox2-4 is built from parts. I started with a KF2 fuselage, modified it (larger tail, wider, switched to nose gear and made new main gear. Replaced the 582 with a 912, made my own KF4 ribs, bought KF4 flaperons, fabricated a KF4 mixer. My DAR was helpful but I definitely made it from various parts from different airplanes and fabricated much of it.
I have to look at my KF2 manual to see what that wing requires but I believe the model 4 has 1.3 degrees of dihedral. Splitting hairs really. Another thing is that the rear spar will have more angle so that you will have washout so you should use the front spar for dihedral measurements.
For what it's worth, I am an 80 hour pilot, all in a Cessna 150. I had the opportunity to take the controls of a Kitfox 4 1050 and had a very hard time flying it. They mean it when they talk about using your feet. After maybe 1/2 hour I stared feeling slightly more comfortable but it was a huge wakeup call. I now have a person lined up with a lot of experience, Kitfox and otherwise, who will do the initial test flights and will transition me. Point is, be ready for that and remember that I have yet to hear from a Kitfox pilot who doesn't love them. Hopefully I will be one of them soon.
I suspect that the airplane was a Just SuperSTOL. http://www.kathrynsreport.com/2021/03/loss-of-control-in-flight-just-ja30.html I wonder if leaving the flaps up and landing faster would have helped. Comments welcome.
Your project sounds so similar to mine. I started with a model 2 but it has the model 4 wing, etc. I used the 3M glue for the fabric and latex house paint. I wore a mask when spraying but it's nice to not have that toxic odor. I also widened my fuselage to 43.5". I think you mentioned a DIY AI. I have two 3.5" 480x320 displays in mine one for the engine sensors and the one shown which receives data from a Pixhawk. I will be flying a club Cessna on Sunday and will evaluate this then. In the photo, the green line in the center is the horizon. The software will evolve once I know the Pixhawk is reliable. Another weird similarity is that I use a skid steer as a snowplow.
Wayne, we are basically a friendly group and I hope I speak for the majority when I say that. Could you take a photo of the flaperon mixer behind the seat? That would settle the mixer concern. BTW, I have a Model 2 with Model 4 wings too. Good luck with the sale.
Some of us have copied the Model 4 mixer but, in my case, I also have a Model 4 wing and flaperons. If I am correct, the Mk1-3 mixer actually gives you more down than up, making the adverse yaw even worst. I imagine it will teach you to use your feet!
For what it's worth, I would suggest downloading a trial of IFlyGPS. I started with Avare but paid for the subscription to IFlyGPS. For less than an hours cost to rent a plane (I'm still building my KF) you get a years subscription.