The 66 convertible I am working on has golden touch am/fm with foot control. Beneath the radio on the lower console there is a speaker fade switch. Can anyone tell if that was a standard fade versus reverb?
http://www.imperialclub.com/Yr/1966/66Owners/23-big.jpg Take a look at the owner's Manual. Not pictured but the Location seems to be right.
Button shown is standard rear speaker switch not reverb. Unless it does pull in and out it will be a reverb button
Which is strange as my '66 has the standard speaker pot without switch, but also has the factory reverb. Does this mean the reverb is always on? Radio isn't in it right now so no way to test. Have you checked the trunk for the reverb unit? It would be located behind cardboard panel just beside the trunk lid lock/latch.