Way cool rig, congrats! Your boat is in fantastic condition.
I also own a '76 CVX-20, 455, but in Orange. It also didn't come from factory with a windshield, lights, ski pylon, hand rails, center console, etc., like the later ones did. They built them very simply first year in production... all beautiful hull and motor!!!!
I kind of like it that way.... nice to see yours kept like that. My boat was modified somewhere along the way with a windshield. I had to reset it & re-drill the holes as they mounted it leaning down/backwards too much IMHO. If it wasn't for that I would have kept ours original like yours, but did add lights later on.
The interior of your boat looks pretty good, nothing beats original if you can save it... is it not pliable any longer, torn or faded? Looks pretty good in the pics!
-Mark