Saving Old Seagulls

Okey dokey. I'll give it a go. Many thanks Chris.

Just bought a Forty minus and not too familiar with it. The HT lead insulation round the conducting wire(s) has broken just where it enters the flywheel assembly. Can see sparks! Needs to be fixed - but how?
How do I get into the flywheel assembly?
The lead is already short so I imagine I will need ...