for awhile, a bunch of NOS flybacks got dumped on ebay. I managed to nab one before they all went gone.

How to restore flybacks and prevent inter-winding arcs, fill in cracks, etc that arnt already carbonized.

You need a vacuum canister with hot wax under an electric griddle or flame to keep the wax hot. Dunk the flyback into the hot wax and pull a vacuum. the air inside the flyback will fill itself in with wax, and moisture will get baked out, and of course wax will fill in cracks.

This will prevent moisture damage and fix corona discharge issues as long as it isnt already carbon tracked.