I've always liked the rear spoilers. I put one on my '67 in '70, when I bought it. Got the spoiler from the local dealer for ~$35. Shoulda bought 100 of them.
My current '67 is an SS. I had a real GM cowl hood for it for several years but decided I wasn't going to use it and sold it around '09, when prices were down. Probably worth 2-3 times what I sold it for now days. Seems to be a theme with me. Buy high, sell low...