After making a 1/2 inch thick spacer block to go under the pivot arm assembly and between the side UHMW blocks, I drilled for a couple more AN-3 bolts. I knew one of the bolts was going to be really close to the edge of this lightening hole, but this one actually broke through. No problem...I'm going to be adding doublers here anyway.

First step was to make some little crescent shaped pieces to fill in the top of the lightening hole. There will be a 0.025 thick x 2 inch x 6 inch doubler over the top of this, with another 0.040 thick x 2 5/8 inch x 6 inch doubler over all that. The 0.040 doubler will pickup the top row of rivets on this rib, and I'll pretty much fill up the area with rivets to allow good load transfer.

The crescent pieces will fill in the top of the lightening hole so that the forward most bolt will have a flat surface for the head to rest against.

After several hours, I had both sets of doublers for the right hand side drilled. Here's the inboard side...sorry, no pictures of the outboard side. Tomorrow I hope to finish this right side arm by adding some more spacer blocks between the two arm pieces, add more UHMW guide blocks, and joggling the forward ends of the arm plates to accomodate the 5/16 thick rod end bearing.