If it were mine to do, this is how I'd do it;
I would not change the radio to adapt a different vibrator, I'd adapt the different vibrator to work with the radio's original socket. The Ebay vibrator is electrically what you need, it's just got the wrong pin configuration. It would be a simple matter to use the original base with it's pins from your dead vibrator to build a home made adapter to make the Ebay vibrator work. With the nostalgia air schematic you've already got the electrical pinout of your original. Somewhere out here in internetland there's gotta be a datasheet where you can get the pinout of the Ebay vibrator. Solder six wires to the new vibrator's pins, connect them in the proper order to the six pins of your original vibrator's base, epoxy it into a small piece of PVC pipe for sturdiness, and run it....
