Since my tube bumper didn't have a mounting solution for my license plate, I finally got around to putting one together this past weekend.
The bumper's tube sections are 2" O.D. tubes so I simply used a couple of 2" dia. conduit clamps, 1/8" thick aluminum plate (6"x12"), & stainless steel hardware. Painted w an epoxy primer and hammer finish paint. Hardest part was waiting for the paint to dry LOL. Easy peasy as they say!