Ha! That's a pitiful drawing but it gets the point across....thanks to Microsoft Paint!
I was figuring on using 1" wide flat-stock....either 3/16 or 1/4" thick. I was going to use 5/16" or 3/8" grade 5 or 8 bolts.....I forget which was the better fit right at this moment. The bolts would have about 3/4" of solid shoulder(no threads)...that way, I could cut off the excess thread part and end up with what looks like a solid pin and has excellent strength and less chance of damaging the adjuster wheel.
I would weld the bolt heads in place. Done.

edit--- I just inspected a regular Toyota adjuster wheel and an ARB wheel and determined that a 1/4" grade 8 bolt will fit with no grinding.