Hey Kevin, you had asked in your original post about where/how the hot air is to exit the engine cowl, have you as yet seen it on the plan?....the plan shows on a front view of the engine cowl to the right side bottom of the cowl (left side of plan view) identifies that there should be a cooling air hole in this location, I assume that this is with the engine cylinder on this side.
I am just now in the process of beginning construction of my own Kingfisher. I have purchased a Sig 104ins Cub wing kit and have acquired a copy of the Cub wing plans and plan on using these to actually construct the wings with some modifications. I did note that the Sig Cub only uses Five (5) 1/4 in spruce spars while the Kingfisher uses Seven (7) so I am planning on changing the Sig ribs to 7 spars.
Information you can use or discard as you wish, I have been asking around for a while about what glue should I use on the fuse of the Kingfisher and the essence of what I have been recommended is to use Epoxy and Titebond III. If you have not yet completed your fuse and would like to consider the Titebond III glue, check out the technical info on the Titebond site, though I have received recommendations directly from their technical department to use this for this application (detailed info given to them previously).
I would be interested on your design related to the rotating undercarriage as I have thought that I would like to incorporate something of this type in my own fuse.