Looking good. Although next time, I'd a use a bigger board.
Just kidding of course!
Actually I would have either gone with a smaller piece of timber, or cut it so the sides of the "neck" portion are longer (if that makes sense).
My point being that spraying the inside of the horns can be a tricky area to get a good paint depth with any jig, but that jig board width and thickness compound the problem. You will have needed to spray at an odd angle (especially the top horn) and I doubt there there will have been a an equal amount of paint deposited inside those horns as the flat surfaces. It could be as thin as just a dusting.
The inside and outside edges of the horns are notorious areas for having sand-throughs.
You may want to consider recoating those areas with primer, and absolutely fix/modify your jig before the colour base coat if you want to avoid the frustration and heartache of sand-through later.