I have a pair. Its been a few years since I did the installation so details are a bit fuzzy. They are fabricated from perforated metal, I am thinking aluminum based upon memory. The perforations are about 3/16" diameter. The guards mount on the opening in the bumper, so they sit about 3-4 " in front of the condenser itself. They are attached on either side of the opening with aluminum brackets that look to be about 3/32 - 1/8" thick. The brackets are just riveted to the guard with pop rivets. Everything is painted flat black.
If you can source the perforated aluminum, making a template and cutting the actual guards to fit should be relatively easy. Fabricating the brackets would be a little more work because of the difficulty in taking measurements in the opening. Each bracket just requires one simple bend (no complex shapes) so once you have the measurements the fabrication process should not be difficult. If you are interested in trying to fabricate your own, I could try taking a photo showing the mounting brackets and mounting location.
They do a good job of keeping grasshoppers and other bugs out of the condenser fins which was my primary objective.