I think Miguel's Chocolate Rocket 1978 has never been opened up. IIRC its got 100k or more on the odometer. Maybe he will chime in. Seems to be the exception rather than the rule. I've read somewhere around here that the life expectancy of valve guides on the 930 is 40k miles. Lots of variables but boost makes horsepower, horsepower makes heat and heat kills.
Other things can easily go wrong besides fueling...how about distributor boost retard failure? That will give you melty pistons and busted rings too.
I'd submit that the heightened risk that the engine needs big $ attention is what has kept the price of the 930 relatively low all these years.
In my opinion this forum is overdue for another rebuild thread.
16volt is far from blowing up IMHO. His car probably still runs great. I drove mine to North Carolina, did a track day, and drove it back with 40% leakdown on a cylinder. Ignorance is bliss...if you're not ready to dive in, best not do a leakdown test