I've stared at the plans long enough, it's just time to do this. Started by drilling a number 30 hole to establish an edge to which I would not cut beyond. That worked pretty well and I was happy with my first two notches. I used a Dremel tool to make the initial cuts then used a variety of files to clean them up and get the shape where I wanted it. A lot of filing and smoothing with a Scotchbrite pad and I was happy with them. I wish the second set had turned out as well but I got a little carried away and they got a little larger than I wanted. Functionally they are fine and will serve their purpose. The edge distance on these is critical as they are very close to one of the holes that you end up drilling for the doubler brackets.

With that step finally out of the way I mocked everything up to check the fit. For the most part the fit was good although I will make some small adjustments to the 6 degree bends that are required on the 6 individual parts that make up the front HS spar.