A suggestion: get a few feet of 3-core mains cable, put a 3-pin plug on one end, fit a 3-Amp or 5-Amp fuse. Mark and note the position of all wires on the auxiliary transformer, and disconnect them. Connect Live to the screw terminal marked "240", Neutral to "0", and Earth to the frame. Switch on and measure the secondary AC voltages across 0 and 9, 0 and 27, and also from 0 to 220 on the primary. All assuming the fuse holds out of course...