Easiest way to remove the bolt is to drill it out, with a drill bit the same size as the bolt, in a lathe. Drill from each end if necessary. Standard drills may be too short to go all the way through.
If you don't have a lathe or access to a shop that does, try heating the bushing, let it cool completely, then heat again and try pounding the bolt out with a punch. I don't think you will destroy the case hardening this way.
And yes, I think a spacer can get it to work with the bushing shortened by only 1/32". I'd recommend the spacer washer to have a hole 1/64" larger than the bolt, and an O.D. 1/64" smaller than the counterbore where the O-ring seats. Then you can tell us what tricks you used to get that little rascal in there. LOL
I salvaged the one on my '67 after completely buggering it on one end trying to remove the arm from the tractor. Bad move for me. Can show scars on each hand from the BFH and sharp metal.
Can't do it now, but I'll check my notes from the '67 and '68 adventures with these bushings. Maybe I made sketches of them that included dimensions. If I didn't, I should have. The sketches in JD Parts have vanished along with the parts.
tommyhawk