Finally getting to some wood working today. I was able to cut out the radius where the trunion mounts will set. I cut lots of slits up to the radius line on our big band saw and then removed the excess with a jig saw that had a ten inch blade on it. Then smoothed it all out with a rasp and drum sander attached to a drill. Once the brass hardware fit the way I wanted it to I marked the holes and drilled them out part way on the drill press as it only plunges 6 inches. I went the rest of the way thru with a hand held drill.
Tip- I used bees wax on the drill bit every hole to reduce friction. It made a huge difference.