Well I finally started working on this again. The super cold weather had me switching gears and working on that heater install, but now I'm warm and done with that so I spent a little time finishing the winch bumper mounts. I finished welding and sanding/painting the bumper shell a week or two back, and had it mounted on the unpainted skidplate/mount- Mainly because it looked good! lol.
I pulled it off tonight, and finished some welds, capped the "high" sides of the frame mounts (to keep mud/dirt from sitting in them), and reworked the winch fairlead/ bumper shell mount. I tossed the stock winch plate, and made a heavier version I could weld on the mount. This made the bumper shell much more rigid. I don't think I will need to bother with bracing the ends of the bumper now.
The Upper frame mounts are for 1.5" square tube, I used 3/16" plate instead. I spaced the bolts with some heavy 5/8" tubing to prevent crushing the frame mounts when tightened. It likely may have been easier to use 1.5" tube, but my method seems plenty sturdy. The bottom plate is one piece, I bent the edges to fit the frame mounts, and then using the spacers, added the top braces. The heavy skidplate ties it into the lower mounts on the frame.
And then this poor pic of the painted bumper mounted