A minor set-back and some perspective

It's worthwhile mentioning at this point that last summer, after an initial investment of just $200, this tractor cut grass nicely. There were a couple of problems with it though. One was that the engine was old and tired: it burned oil, blew stinky smoke out the exhaust, was finicky to start when hot and had an annoying habit of backfiring. Those problems will be solved with the service rebuild I'm finishing up now.
The other problem this tractor had was that the spring pin that connects the engine to the transmission input shaft had a tendency to break. Like every 20 minutes. It even broke while I was driving the tractor home after purchasing it! :) Actually that first time there wasn't a spring pin in there at all but a POB. I replaced it with a spring pin and thought "great - that problem is solved!!". Not quite. The deeper issue became apparent when I removed the engine from the frame last fall - only three of the four bolts that hold the engine in the frame were there, and of those only one was tight. That improper mounting let the engine slop around in the frame and certainly contributed to the broken spring pin problem (I hope that was the only cause, but that remains to be seen).
The set-back was that when I was tidying up the threads in the engine, getting it ready for mounting, I discovered that the threads in one of the holes was totally stripped. Three out of four isn't going to cut it, so the thread has to be repaired. I chose to use a Heli-coil insert (a relatively cheap and better-than-new repair) but unfortunately that means I need to pull the oil pan off the block again (where these threads are) in order to do the work. This will take a few days. Plus I don't have the tools to make the repair myself: I bought a box of inserts today, but after pricing the full repair kit ($90 for a special drill and tap) I couldn't justify that. I'm hoping that my friendly machine shop will do this for me either for free, or for a token fee. Depending on the cost, I may have all four done at once and then the engine will never vibrate loose again.

Tidbit: Did you know that 250,000 Heli-coil inserts are used on each Space Shuttle? Yes, that's one quarter of a million. Same with Boeing's 747's: each one has over 250,000 of these inserts. Cool.