I'm retired so I'm cheap. Here's what I'd do (now that I understand the problem)....I'd take a pair of sharp scissors and cut a strip of aluminum foil no wider than the threaded top of the spark plug, wrap a couple of turns of the foil around the tip and shove the boot on. I have the same thing going on on the T100 on the right cylinder and that's how I fixed it. The retaining wire isn't retaining anymore.
Geeze Jack....no copper anymore.......