I received a few like that from paypal. I also got one from UPS about my package not being delivered. The only thing I ordered lately was shipped FedEx.
Know how you feel. Had a GN in 89 to 92 and got the itch also. Had a recurring dream I had my GN and woke up bummed out. Fixed that 2015. Enjoy, I know I have.
Would a place even mount them being so old? I made the mistake of buy original speakers that were removed when the car was brand new and stored inside their house. I put them in and cranked up some SLAYER and they blew to pieces. Just because they look brand new doesn't mean they are like brand new.