Are you sure they had a "boot" on either shifter or brake lever?
I know they had a thick foam sort of rubber donut between floor cover and transmission. I'm not an expert on the little details like that on these AD trucks but still don't think I've seen remnants of an original boot for either.
The manual page isn't working at the moment but looking at the pictures in the shop manual is a good way to find out.
http://chevy.oldcarmanualproject.com/Grigg
