I have a model IV with the two part doors. Actually three parts. Polycarbonate top and aluminum bottom with a fiberglass strip between and overlapping both.

The instructions do state that the fiberglass strip is riveted with the metal to the lower of the two center tubes but it does not mention riveting the polycarbonate except at the top and the sides. What have others done? Seems that the bottom of the window and the top of the fiberglass strip will be pretty loose.

The instructions state 1/4 x 1/8 aluminum pop rivets for the metal to tube and 1/4 x 1/4 for the fiberglass and metal to tube where they overlap but no mention of rivet size for the polycarb to tube. It is close in thickness to the fiberglass and aluminum together so I am thinking 1/4 x 1/4.

Thanks!

Henry