A stripped spark plug hole looks like a new-head sentence, and it almost never is. The thread is M14 by 1.25 on nearly every small engine that matters, one repair kit fits the family, and the decision tree between a $38 Heli-Coil, an $80-plus Time-Sert, and an actual new head is shorter than most owners expect.
The 92-6518 traction cable is sold as one sealed piece, so when a Lawn-Boy or Toro stops self-propelling, most owners replace the whole thing. The real failure is a small spring at the engine end, and you can swap just that.
A snapped recoil spring doesn’t have to end a forty-year-old Lawn Boy C-12. The OEM spring (602610) is no longer made, but the Stens 155-051 crosses straight to it for about $5 on eBay — here’s the exact part to buy and how to swap it safely.