My '66 GT has a bunch of stuff on it. 8000 grand Rotunda tach, Bendix AM/FM, locking glovebox, accessory sill plates, cable trunk release, etc.
I never installed the Studiosonic reverb / rear speaker, but I have one of those NOS.
As the drill sergeant said, "I taught you everything you know. I didn't teach you everything I know."
"Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so."
- Douglas Adams