What type of reverb unit did those Motorola console stereos with Vibrasonic have? I'm guessing they had a mechanical delay line with springs, but I'm not sure.
If the delay line was the type with springs (as the old car-radio reverb units had--my dad had one in his 1963 Chevy BelAir years ago), one would have to be careful not to jar the cabinet too hard, lest the springs bounce against each other. The loud "BONG!" one would hear from the speakers when the latter happened is a sound one would not forget in a hurry!
BTW: Hmmm. I don't think the Moto consoles had mechanical delay lines at that. I say this because of the variable "Vibrasonic" control on the stereo control panel; I cannot see how a mechanical delay arrangement could be regulated by such a control, unless the console had some sort of all-electronic reverb system.