I accumulated all the hardware a few months ago, but finally got to it today.
I used 2 pieces of 4 1/2 " long, 2"x2"x1/4" angle iron w/ a 1/4" gusset plate welded in just to help keep it from twisting under load. Both were bits of scrap from a local metal shop, cut w/ a chop saw. I notched the lower edges to minimize cutting on the bumper itself. I just used a sawzall w/ metal blade for that.
The rings are 10,000 lb forged Crosby units I picked up at the local Rigging Supply shop for $10-ish ea.
The 3/4" bolts w/ washers were another $5.
Drilling the 3/4" hole through that steel really was pushing the limit for my drill press!
I replaced the center bolt w/ a 12mm bolt just for added strength and I moved the original bolt to the top position.




