Help for possible Broken Piston Rod please.

Good luck on your rebuild, sounds like you're in the top 5% of TW forum readers as far as actual experience tearing down & rebuilding.

In future I would consider maintaining your oil level so that it is full (but not overfull) at all times. Never lower than ~15% below the top dot, especially if you drive it hard. That and of course changing it every 3500 to 5000 (max!) miles, OR every 6-9 months whichever comes first.

I'm not saying that the half-way mark on the dipstick was specifically what caused your problem, it was much more likely the sludging you described, but keeping it fuller on average (after a good clean-out) should reduce the tendency to sludging in the first place. By keeping a somewhat lower average oil temperature (larger total volume of oil passing through the engine, carrying heat away) and by having a lot more oil available for contaminants to be dissolved/dispersed in.