I made one 10 years ago for my 4120. I used a wooden frame, constructed from 2x2's, and a brown-duck canvas boat cover over top. It has held up better than the factory fiberglass one on my prior Ford 2000. Plus it is larger, lighter, far more effective at blocking the sun, and much easier to mount/dismount. I tapered it a bit towards the front, to make it slide easily along the trees on the hedge-rows, and have used a little bit of duct-tape to patch it a few times over the years. Took me about 2 hours to make, and is far more effective than any factory model I have used. I attached it to the top of the roll-bar with a couple bolts (drilled 2 holes), and added metal, diagonal support rods below on each side that attach to the existing holes in the roll-bar fold mechanism. It ways about 50 lbs and takes less than a minute to put on or off.