Well, according to electrical diagram: Gerätebank rechts, P2 for MG17, P1 for wing root 151/20 and P? for wing 151/20. I think those are the circuit breakers and were not usually used to select weapons, just to power them on or off for loading and maintenance. The actual arming switches are on the same panel as ammo counters (SZKK 4) and they are usually grouped in the same manner as the weapons are fired, that is fuselage+wingroot together and outboard separately.
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