My question would be “why is it contacting?” Did the insulating coating melt?, if yes than why did it melt? Is it worth trying to figure that out
A spinning magnet over copper will cause the copper to generate it's own heat, in some cases the copper will glow orange. Over time, the coating probably deteriorates. Toss in a problem somewhere else in the electrical system, maybe creates more heat. Add in thermal expansion/contraction, where the wires may shift to wear the off the coating and/or contact the core.
Contacting the core let's the winding ground to the engine. That's why I'm wondering if the eddy current still happens if the windings touch an insulated core.
If it would work, three non-conductive sleeves and three fiber washers would fix this. But I'm thinking probably not, or surely this would've been done already.