I don’t have a drill press and no demonstrated measuring skills. I couldn’t find a solution on Etsy so I asked my machinist friend for an idea. Here it is.
that’s right, a self centering L-track jig for the measuring impaired.
Yes. Drilling your own holes and counter sink is literally a time sink. I have both kinds (4” pre drilled and custom drilled) in my van as I am using flanged l track for both floor cargo hold down and wall panel retention. The counter sink should be slightly larger overall diameter of screw head to avoid that oblong look in the l track channel.
BTW: all these years and I learn metric is 90deg and fractional is 82 deg counter sink. This was a revelation just like learning that womens blouses button opposite from mens.