The spray pattern may look random but it was quite specific in many ways. When they were primed and sealed (brick red and grey colors) they were hung two at a time with the undersides towards each other and the fronts pointed towards the ceiling so they looked like a giant clam. The drain holes pushed them away from each other at the front so there was a 1/2 inch or so gap at the front and the rears were touching together. They were typically hung from one of the drain holes which skewed them a small amount so they didn't align perfectly, this is why you often see overspray patterns on the undersides which show features like dots and lines from the overlapping bolt holes and slots at the rear and sides which blew through the opposite scoop that was hanging with it. Then once they were dry it appears that the final paint (black Organosol, Silver Argent, etc.) was applied after they were set individually on a flat surface with no masking which shows over spray on the underside due to the drain holes holding the front up and a short distance away from the resting surface and from painting through the front openings.

So, accordingly, for those going all out on a proper restoration you'll find it much easier to use two scoops (one to act as a mask for the other one) to duplicate these details 100%.