Thanks!
The bolt-on rear spoiler is made of brass. I hand cut two identical pieces from 0.010 sheet. Then drilled 19 holes in each and scored one side of both for the upper "tabs".
The upper "tabs" were bent using an angle template for continuity.
Then I soldered them together. This is the rear side.
I acid cut a recess that will accept a clear spoiler element/window. This is the front side.
