Alternatively, you could buy the set and then sell the extras to other people in the same situation, on eBay...
Kind of a hijack, but related. After reading this yesterday and going to the Moss site to look at the price of the complete set, I clicked on the mounting instructions link realized that Moss has got these things wrong. I got a set from them last year, set up the way the instructions show, and thought it was just a manufacturing error -- but the instructions are for the way I received them -- kinda backwards.
I reversed the clamps, so that the fat side of the clamp with the set-screw faces INSIDE the car. This works better two ways:
1) The thinner side out, doesn't push the side curtains as far away from the tenon plate, when both are in use.
2) With the set-screw to the inside, the slot will step over the windshield frame allowing the clamp to push further onto the tenon plate at the top clamp. If it's the other way around, the set-screw is sort of barely on the edge of the tenon plate.
I have never seen an original set, so I don't <span style="font-style: italic">know</span> for a fact that this is true -- BUT -- my car came to me with set-screw marks on the tenon plate from a pre-1983 installation of wind wings: ON THE INSIDE of the tenon plate.