Not that familiar with the Eager Beavers- pulled apart a few 310's and they are similar.
Does the main HT line not unscrew from the coil? What is under the grommet where the lead enters the coil? If it does- you can replace the line.
If it doesn't you can pull the cap and the coil spring thingy that fits the sparkplug and slide some heat shrink tubing over the HT cable- if the wire is not broken inside, just the insulation cracked, that will insulate it fully for a while and easily replaced.