I finally bought myself a #10 drill bit so I could drill the flap blocks. I marked one hole per the drawing and then drilled it through the block with the drill press.
Then I clamped the block in place with a scrap spacer and one of the bolts. I then turned it over and started the second hole with the hand drill using the hole already in the bulkhead.
I then removed the block and finished the hole on the drill press.
I was disappointed to find though that the block no longer sat square to the bulkhead flange after drilling. Not sure how I screwed that up. I'll have to think about it.
