Here's the way I did the outboard struts on my Bucker Bipe:
I bought 8 Goldberg nylon control horns and cut the base off each. Can't remember if the ribs were already plywood, but if not, I backed them up in the strut area with some ply. Then I bolted the nylon horns to the ribs with 2/56 bolts and nuts, two per horn, leaving the small end of the horn sticking out of the wing about 1/4" (out of the top of the bottom wing, and bottom of top wing, at the strut attachment points).

I made the struts of 1/8 x 1/4" spruce and roughly airfoiled them. On each end, I cut a slot (running fore and aft) and glued in a steel landing gear retainer (that used for fixed gear, the steel strap with a hole at each end). I drilled through the strut where the hole is in the strap, and drove a short piece of 1/16" brass tubing into it, filing it flat with the outside of the strut. Now you have half of the steel retainer (strap) sticking out, with the hole in it, and you use a 2-56 Allyn head bolt through the strap and into the nylon horn which will self tap, and never vibrate loose.

Of course you have to make sure you make all of these the correct length so as not to force a warp into either wing.

It is easy to assemble the airplane and the nylon never wears out and gets sloppy. Been working great for 7 years now!

Clair Sieverling