I finished deburring the lightening holes in the box and then drilled the brackets to the battery box remembering to use a piece of scrap to offset the pilot side by 0.20" to simulate the firewall recess. I cut the battery hold down bar to length, rounded the ends, drilled the lightening holes and then set it aside. I rattle-canned the box black after dimpling the rivet holes. When it was (mostly) dry, I riveted the brackets to the box and then marked the bolt holes in the hold down bar to line up with the platenuts in the brackets. I could have drilled them as per the plans because they lined up perfectly.
