I’m not going to say the "best place" but I have used these guys to rebuilt my power booster for my 70 340 Cuda and had good luck with them. I think they sell parts outright as well but you will need to check with them.
Booster Dewey Power Brake Booster Exchange Inc.
I was cleaning out my garage this weekend and found a bunch of Cuda parts that I no longer have any use for.
Misc .1970 Cuda Parts (prices do not include shipping)
" Hood Pins (used, just the posts and nuts, no hood clips) $20 OBO
" Rallye dash light bar wiring harness (used). $20 OBO
"...
I have added some pictures. This headliner is still in the package sealed so I can't really get good pictures of the black side. You can see the perforated pattern as well as a little bit of the black (interior side).
Just for clarity this headliner is only for 70/71 Cuda's
Ships from Tempe...