Bob, Trying to adapt a 9 volt battery would require some major modification to the battery area. The way that the switch is located, to pick up the + side, and making the - side connection, would destroy the battery cavity. The best solution, to retain the existing battery holder, is to make an adaptive battery, close to the original design, that keeps the original dimensions. TJ, will probably try the solution before I do, and knowing how meticulous he is, it should come out fine. My choice of battery, would be a 123A, camera battery, with nominal 3 volts.
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