Hi 38
Now you have a coil with a short length of HV wire on it. If the coil is still good, here's what I do. Take a crimp on non insulated butt connector for 14-16 gage wire, a length of new 7mm HV wire, some 1/8" x 1/4" fuel line (Tygon works just fine) and shrink tube to fit over fuel line and the ferrule on the coil. Strip the end of your new HV line and connect to existing wire, melt solder into connector and cut new HV wire to length. Cut a length of the fuel line equal to the distance between the coil and the end of the insulation on the new HV wire. Slit the fuel line and slip over bare wire. Slide the shrink tubing onto the new HV wire and slide down to the coil so it covers the ferrule and shrink into place. Attach spark plug cap to end of HV wire and you're good to go.
If you want, you can use 2 different widths of shrink tube, one to cover the wire and fuel line, the other to cover the ferrule and the smaller shrink tubing. This operation can be done without the solder, I just feel it gives a failure proof join. The 1/8: x 1/4" fuel line works to replace the missing insulation and the shrink tubing holds everything together. If you're really fussy, silicone sealant can be applied to the slit and both ends of the fuel line before installing shrink tubing. Hope this gives you some ideas with which to work.
All the best,
Sky