Patrick, your silicone idea might be the best, considering the Venus is a glow airplane. I used the foam tape a lot in the past and never found one that stood up to glow exhaust.
In case you haven't done it, you tape wax paper to the top of the wing, squeeze a bead of silicone onto the seating area on the fuse (with your shims in place), mount the wing, clean up the squeeze-out and walk away for a day or two.
You can still peel it off if you decide to change the incidence.

Scott