For the nets, we send a cardboard template to Mastercraft, with the axact shape of the net desired. On the template we note the locations of the rods, or whatever the fastening method is.
I can get you all the hardware, with the buckles. Let me check on the price.
We used to build some of the nets with elastic in one end, and used a mechanical retaining method for the upper bar. Since Johnny Greaves' crash at Pomona last year, those have been outlawed. Seat belt style buckle (either push button or cam over) is now required.
Engine Specialists, Side x Side Parts & Accessories, Discount OEM Parts