1965 fastback

We have been working on our father son 1965 mustang Fastback for the last 6 years. We bought the car completely disassembled with lots of boxes. As we near the end of our project and installing final peices we found these in the rear quarter vent box but can’t figure out what they are for...

I am considering buying this project, I am just not sure if what he is asking is worth it. $8500. What do you think?