I sent an email to Sonex tech help to let them know that I went ahead and just made up some ribs from sheet AL to fix my problem. That’s when I found out that Sonex has the SNX-Z02-04 channel they could have sent me. Well, live and learn. Apparently the older kits were supplied with it before they produced the laser cut option.
Just to be clear my tail kit was one of the first laser cut kits supplied so I don’t expect to have these problems on the rest of the kit that I purchased this year.
Good news though, Sonex confirmed I had the skins on correctly. the straight edge of the skins for the horizontal stabilizer is the bottom and the curved edge is the top.
Time to rivet.