here you go mate, on else off/crank else center controls for both engines
{down = device_commands.ENGINE_Crank, up = device_commands.ENGINE_Crank, cockpit_device_id=devices.ENGINE, value_down = 1, value_up = 0, cockpit_device_id=devices.ENGINE, name = _('Crank Left Engine Else Crank Center'), category = _('Engine Control Panel')},
{down = device_commands.ENGINE_Crank, up = device_commands.ENGINE_Crank, cockpit_device_id=devices.ENGINE, value_down = -1, value_up = 0, cockpit_device_id=devices.ENGINE, name = _('Crank Right Engine Else Crank Center'), category = _('Engine Control Panel')},