Analogman SD-9 Silver switch mod help

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My AM SD-9 (Ibanez) has been modified by Skrydstrup to have the circuit always on, regardless of the led/switch state - great when using a looper. However, I want to put it back on a small pedalboard, and so I need to be able to switch it on and off...  When I look at the circuitboard, there seems to be one part removed (Q104). Any ideas on what part to put back in, and where to get it?

All input appreciated.

Thanks,
Mike