I went back and looked at David's original build. If you are getting this from looking at his cabal reports (#13 shows the area in question), then I think you are misinterpreting what is shown. Both David and I cut the skeg/strut part into two sections (my cut is more forward toward the strut than Dave's). But we both glued the forward section with the shaft struts permanently to the hull. The screw shown in Dave's photo was only there temporarily to hold the piece in alignment until the glue joint set up. He states this in the text. We then used different screws, not seen in the photo, to make only the rear section (and thus the rear planes) removable. I used two screws, I'm not sure how many Dave used. Of course Dave may have changed this arrangement once he went into production, but I have not seen the final version and couldn't say. I will say that I find that the shaft actually gives a great deal of support to the strut, and not the other way around. It has given me no problems.
George "Crazy Ivan" Protchenko
“There are the assassins, the dealers in death; I am the Avenger!”-Nemo
"I'm disinclined to acquiesce to your request; means No!"-Capt.Barbossa