When I looked back at Wilson's boat, it looks like he has the factory installed spotlight. He could probably measure it for you.
The one in Montana may be the one that is in the photo in the ACBS Rudder magazine. There was a group of folks that took a week long trip on the Snake River or Colorado or some river out west.
I also noticed that both Wilson's boat and yours have trim tabs. I bet they make a big difference. Anytime the boat has extra weight in the back, it wants to bounce up and down even in calm water. As soon as you bring a little weight up front, it rides smoothly again. I thought of adding a little larger wedge to the current factory wedge set up.
1969 Chris Craft Cavalier Ski-230 HP 327Q