My '69 does have the AM/FM stereo receiver with the separate amp over the glovebox. It's not the reverb unit that was also available. I don't know the pinouts, but they could be had from a radio rebuilder. Check the section on this forum.

I opted to retain the original AM/FM stereo receiver in-dash, and instead of reinstalling 6 x 9s in the cardboard boxes in the trunk of my 'vert I installed an Infinity BassLink subwoofer, which takes very little space and allows the top to fold away nicely. I then cut the rear power top cylinder covers and installed Blaupunkt OverDrive 5 x 7 shallow speakers, which clear the mechanism with room to spare. I then replaced the factory 4 x 6 kickpanel speakers with new Infinity reference 4 x 6 speakers, and a new head unit installed in the space between the console and the bottom of the dash, in a custom vinyl-wrapped box.

For show purposes, I have the old 4 x 6s magnetically mounted under the dash on the old harnesses. I just need to demostrate that it works, not that it sounds good. The new head unit uses quick-disconnects so I can pull the whole thing and tuck the new wiring up under the dash for shows. If I need to display the trunk, the BassLink removes with two screws, then the power, feed and remote leads.

I plan to have a spare set of panels to install in place of the panels with the 5 x 7s, but haven't gotten that far yet.

There is no compromise in sound quality, it's all reversible, and retains the original hardware. I've seen very nice completely trunk-mounted installations that use a remote for switching sources and channels, and a fiber optic cable to point the remote at. I considered it, but I wasn't that concerned about invisibility.