During the late ‘70’s I was working at an auto parts store.
A guy comes in madder than a hornet and shoves a brand new Champion spark plug in my face that has no threads on it. His story was he was out in the Gulf of Mexico and when fishing slowed down to nothing he decided to change the plugs on his boat. He took the old plugs out and dropped them in the ocean and the last one he took out of the box was the threadless one. He claimed he had to be towed in by the Coast Guard because the engine would not run with one open hole.
Back in the early 90s, I bought a new Frame filter that had no threads cut.
When I tried them on in the store I could see fine, but somebody's leather jacket had a weird glare on it.
I didn't think much of it, until that weekend when I had the sunglasses on again, and stopped behind a car at a light, the glare off the car was shimmering.
At that point, I kind of guessed that the polarization was off.
Sure enough, I held up a pair of standard polarized sunglasses to look through, and one of my lenses was ground with on the vertical polarized axis (compared to the usual horizontal).
In 1972 I was managing a gun shop in Sacramento California where we got in a set of Winchester 1866 commemoratives. The set were these gold plated model 94 rifle and carbine in .30-30 with fancy walnut in a supposedly "limited edition." But Winchester didn’t really grasp the concept of limited and made 100,000 in the limited editions of their early commemorative guns.
One of the other failings of the Winchester commemoratives was they cut corners on the basic gunsmithing instead of making them higher quality, because they figured they’re more likely display pieces. They put effort into finish, but scrimped elsewhere on these commemoratives, especially on internal fit and finish.
These both had the 24k gold plated receivers and nice blued barrels, triggers, hammers, and levers, and the barrels had the Winchester stamping with PROOF MARKS showing they’d been test fired at the factory.
Only one glaringly huge problem: neither the rifle nor the carbine had ever been chambered to take a .30-30 round! They could not have ever been test fired! There was literally NO CHAMBER on either gun! The bore was straight rifled .30 from breech end to muzzle. Somehow they neglected that step at the factory. . . Oops.
One gun I could see how that might happen. . . But TWO, one a 24" octagon rifle barrel, the other a 20" round carbine barrel, which you’d think would have come off different lines, and BOTH missed being chambered winding up in the same matching serial number set? Something was fishy at Winchester, but they weren’t talking.
We sold the set as a factory error for five times what the MSRP for working guns would sell for, even though Winchester was demanding we send them back to be chambered. Winchester didn’t realize their return demand letter was an admission they were genuine factory errors.
That’s why you never dispose of the old parts until you have a successful test drive. Working on a boat while out on the water seems foolish to me in the first place.