Good luck with your ‘40. Sometimes it good to look through the suppy sources for pictures of the correct parts. After these many years, few are original and things like shift boots, knobs, paint colors etc. will be hard to figure out. Here a list of sources I keep on my “notes” on my computer and phone to refer to for reference and purchases.
‘37 Jim Carter (oldChevytrucks.com) chevsofthe40s.com fillingstation.com classychevusa.com bowtiebits.com classicindustries.com iandireproduction.com 38chevy.com hotrodssheetmetal.com chevysupplyofassonet.com earlychevyparts.com speedwaymotors.com Classicparts.com https://newportwipers.com/ www.vintagepartsclub.com
www.steelerubber.com americanclassics.com and lmctruck.com have limited amount of pre AD parts but do have some. Mar-k.com https://directsheetmetal.com/collections/chevy-pickups Resouces of Information including the Stovebolt Forum (stovebolt.com) Vintage Chevrolet Club of America (vcca.org) Chevy.oldcarmanualproject.com gmheritagecenter.com
http://chevy.oldcarmanualproject.com/models/ http://devestechnet.com/
http://chevy.oldcarmanualproject.com/ lots of info here.

Larry
Old man᠁Old truck᠁neither one goes very fast. All you need in life is TIME, PATIENCE and MONEY.
If you are missing one component, you'll need an abundance of the others two.