Great info. Thanks to all for the replies. I found a good picture on the net. https://photos.app.goo.gl/63XLCJkeAq1AcuG68

I agree with what Kent said except, I think both holes marked 6a are original as I see them on other vehicles. https://photos.app.goo.gl/1fRyZzMm4rxs2mNC8

My guess is the lower 6a and the hole #8 are for clips to secure the wire from starter to amp gauge. The upper 6a hole is still a mystery (to me).

Also, I don't think hole #10 is for the toe board/floor pan. The floor pan screws into a center cage nut but that's not hole #10. Hole #10 doesn't correspond to any hole on the floor pan so that one remains a mystery. Here's a better photo with a green arrow pointing to where the center cage nut is missing: https://photos.app.goo.gl/9rU1KRv4uouJt7Cv9

Thanks for the help. I ordered some cage nuts and in 12 hours holes #2 and #4 will be filled!

David