Chick, Thanks for all the info you post, it has been a big help to my restoration. I just finished my diff. thought I would pass along what info I found & ask for advice.
My car is an 11A Nor built car. I assumed the car build started Nov 3-9 1968, but the diff was stamped Nov 11Th and the inspection stamp date on the brake adjuster is Nov 16 (316). I thought you posted a picture of your stamp date but I can't find it.
My diff had very little paint on it but the backing plates had very thick black paint. They were dipped & hung because the paint was thickest at the top of the plate. My brake adjuster arm was dark in color kind of a dark blue-black color, I think it was dark phosphate. My springs were the same colors that you found, but I didn't find any paint on the brake shoe retainer caps. The large nut holding the top shoe pivot was copper plated. After cleaning, plating & assembling everthing it kills me to paint over it. I really don't like the look of paint on the parking brake cables, looks sloppy but correct I guess. I would like to get my car judged after I complete it, and I wonder if a judge would deduct points without paint on the cables & bolts. What would you and others do?