Rear Shoulder Strap Issue

Help me out here fellow 8'ers.

I am trying to secure the rear shoulder straps to the F-858-1. The plans show putting the AN4-5 Bolt through from the side toward the skin. My F-858-1 is already riveted in place, and the gap between it and the skin isn't big enough to push the AN4-5 through. The gap is about 18/32" and the bolt is about 13/16", so I am 1/4" short

Was I supposed to put the bolt in there before riveting?

I can't turn the bolt around, because of the Castle nut with cotter pin. How to fix this? Do I need to drill it out, and re-rivit? I hate to do that, given that loads really matter here. Am I just being stupid here, and missing something obvious? Any suggestions?

Also, did I miss some place in the instructions (Page 8-67) or plans (Pages 32 and 38) that tell me to put the bolt in first?

Bolt issue

I installed the bolt bottom up and used an nylon lock nut as used through out the aircraft.

I believe using a nylon nut is a no-no in situations like this. The harness needs the ability to swivel to ensure the load is not focused on one side or the other, so a castle-nut/cotter pin is used so that it isn't held tight by friction.

Good Point

A good point regarding the movement of the attachment point. I however felt that this was not an issue since the shoulder harness passes through the rear bulk head slots and side to side movement is not possible or desirable as this could result in a "sawing" action on the straps. I also lined the pass through slots with some padding material as added protection from abrasion. That's the beauty of an experimental...many ways to skin a cat.