There are thousand upon thousands of hardware store guns and lesser field grades that never made it to the new millennium. The newly prized Sterlingworths did, and were subjected to the same torture and abuse the clodhoppers could heap upon them as the store boughts.
Its a numbers game - prolly as many Boss&Co guns have failed as Sterlingworths over these many years.
Some here are too Sherlockian in their thought!