Thanks! Before I reinstalled the main board, I removed a bit of corrosion.
Here's a closer look at that flyback. Some material has melted out the bottom but otherwise it's in OK condition.
Now, I've moved on to working underneath the chassis. It appears to be 100% original. Even the filament dropper and thermistor test OK.
That sand coated dropper is showing green corrosion though so I'm inclined to replace it.
This big multi-section cap is crusty and bulging
