Building my first CBG using Make Magazine plans (most recent) and I am electrifying it using a Radioshack piezo part #273-0059 (2700 +/- 500Hz). 

I have two questions:

1) The piezo I have was in the plastic housing with a circuitboard.  From what I have read here on CBN, I am supposed to cut away and throw away the circuit board part of the piezo, leaving me just the silver disc and trailing wires.  There are 3 wires, what is probably signal, ground and one for the microswitch for the now thrown away circuit-board.  Should I ignore the middle wire and just wire the signal and ground wire to the phono jack? Is that correct?

2) Once the piezo and phono are wired together I now must mount the piezo.  I plan to mount it between the stock of the fretboard and the cigarbox lid directly beneath the strumming area. I have read and seen various methods but should this disc be totally glued down (immobilized) or as it was mounted within it's original plastic housing where a small rubber ring on the silver disc acted as a pedestal keeping the silver disc held up for max vibration?  I have also seen here on CBN the piezo glued between two pieces of wood so it is effectively inside the stock.  Doesn't it need to reverberate or something or are the frequency reverberations picked-up even when totally glued down or smashed between two surfaces?

Any guidance is much appreciated!

Steve