[Arran]

Fred;
  The chassis in your 118 looks much better then the one in my 3118, I think that yours would have cleaned up pretty decently with my standard TSP chassis wash at the height of summer, followed by a spot treatment of navel jelly or phosphoric acid for the bad spots. My chassis has some thick crust in places, thanks to rodent activity most likely, which will require the phosphoric acid treatment as I think that these are like a Philco 60 or 81 in that there are aluminum cans that you can't remove. One common failure point in these sets is the big wire wound resistor across the inside rear apron of the chassis, it's a bleeder resistor used for regulating the B+ supply, which this set needs because of the class A-B power output stage. The speaker voice coil could likely be rewound if need be, or it may just be a case of a broken lead wire.
Regards
Arran