Just a few hits with magic erasers, 409 and papers towels has it looking more approachable the next day.
Now that most of the mildew smell is gone, it is time to start removing all the major internal components to do some repair to the cabinet structure itself. The slightly swelling walls towards the bottom are not much of a concern because the original material itself is there and should not deteriorate further unless for some terrible reason it becomes water damaged again in the future. I would rather not make it look worse trying to remove swollen MDF. 30 year old things should show a few battle scars anyway. However, the damage to the actual floor of the machine must be repaired. A whole corner was broken off and thrown inside the cabinet, and the other front corner bottom is pretty rough.
Time to open it up! Everything is all original inside. I was relieved to see it was the original Wells Gardner monitor instead of some hack or Kortek crap.
After carefully removing the glass, I set it down on a drop cloth to tape off the transparent area of the glass, getting as close to the round corners I can with bits of masking tape. No dust should accumulate on the backside, so there should be no need to try to clean before painting. I sprayed a tad of this glaze onto a paper plate and dabbed a model brush in it and applied it to the flake shown in the previous picture. I spray 3 coats of Krylon Clear Glaze on. That effectively re-glued it to the glass before it was sealed.
Time to glue. Locktite III does the job well. Used a 24 inch "bar grip" in reverse to push one end up against the bottom of that metal coin box holder shown above with the broken piece underneath. I put enough pressure on it to hear a slight crunch after applying the glue and left it for 24 hours.
Now that the glue is hard and the clamp is removed, it is time to add some "body filler". I chose Bondo. One thing I always gathered from auto body guys back when I delivered paint was "Fill the holes, but spread thin." so I tried to do that, as well as using the spreading technique to mix a small bead of hardener into the filler rather than stirring it.
Letting this cure overnight. Also applied some inside the other side of the glued part. Tomorrow I will sand it, apply another coat, and repeat until these 2 corners are level with the rest of the floor. At that point I can spray both sides of the bottom and inside the bottom to about 12 inches up with clear coat.
I am really looking forward to working on the monitor and wiring up a new power supply to boot this thing!