Thank you for the photos. Here are my findings:
100V setting = J2, J3, J6
120V setting = J1, J4, J6
220V setting = J3, J5
240V setting = J4, J5
Regarding the auxiliary transformer: if the unit is configured for 220V/240V, you must replace the transformer with one rated for 220V/240V. If configured for 120V, you may connect a fusible resistor in series with the primary winding of the auxiliary transformer to step the voltage down to 100V.
Best regards,

