Bruce, MTH is selling it all in one package. This is the stacked board, bottom board and cradle part number AE-1000035-5V. If you need the set to replace a 3V board it is AE-1000035-3V. This is my all time favorite board. I stock up good each time a fresh supply shows up at MTH. I only have a few left and have an order in place. You are a tech and have access to have your 5 volt sound file converted to a 3 volt file. Not a big deal. The only thing to remember is you need special chain files for the 3/2 boards. If you do not have them handy and need them, let me know.
Go in the MTH tech site and you will see the service bulletin regarding the newer numbers.
Marty