But here's a story that I heard about three decades back, that might fit into the U.L. category.
A college buddy and I were on our way back to West Lafayette in the '70 Valiant (225 /6, 904, beige, invisible to cops) that he'd inherited from his folks during that year's Spring Break. I'd flown to DC to meet up with him, then we meandered our way West via the Philly burbs that had been my home a few years earlier, then his old stomping grounds near Pittsburgh.
At a party we went to outside of Philly, one of my Mopar-devoted friends told me of an engine deal he'd heard about that seemed on the "too good to be true" side.
Seems that about nine years earlier, there was this shipment of new-in-the-crate, complete-from-air-cleaner-to-oil-pan 426 Hemis that disappeared on its way from Ma Mopar's Marine & Industrial Engine plant in Marysville, Michigan, near Port Huron, and the Newark (Delaware) Assembly Plant. The truck and trailer were later found, empty and torched, at the bottom of a quarry.
Accoriding to my friend, those Hemis were now available for $200 each, or five for $500, still new-in-the-crate and complete.
Not having that kind of cash on hand, or anything larger than my buddy's Valiant to carry them in, I declined.
If that doesn't define the term, "Could-woulda-shouda," I don't know what does!