I am building from the kit. I found the answer to my dihedral question, but I AM concerned about the wing thickness. I am using Robart retracts and they are thinner than the retracts that Royal offered when they were in business -- but it looks like they will just fit. I already have built the upper wing, so I really can't change the depth of just the lower wing at this point without making it look strange. Such a change would require a lot of custom cutting of new wing ribs in any case. Getting the section would not be difficult as there is an online site that will plot out the outline for any chord length you want, but there are probably 40 ribs you would have to make and cut out. The thickness and size of the wheels are also an issue. The correct size wheel for this kit is really 3 - ½ inches, but you have to reduce the wheel you use to 3" to fit in the space forward of main spar, but behind the leading edge cap to fit the Robart retract mechanism.