Being from U.K., there is a fuse in the mains plug. If this is replaced with an Australian plug, the unit becomes unfused, and that could be a problem because something caused this fuse to blow. That rubber insulation looks pretty sick too. At this point, the unit has not been connected to power. That will come after visual inspection and replacement of all suspect parts in the amplifier and power supply.

The arrowed parts do not appear on the circuit diagram to which I have access. I would be more worried if they weren't here either. The capacitor to the left is part of the self-biasing arrangement for the 6V6 amplifier tube. The schematic has only a 0.05uF capacitor in this position. This unit has that, as well as this 50uF electrolytic. The two resistors and the other electrolytic are the final stage of filtering for the HT line before it goes to the keyboard.

The speaker has been mounted in the box again, with a piece of aluminium mesh to protect the cone. Whatever had been there previously was long gone, exposing the cone to damage.