From my understanding, a lot of that was “slippage” by employees and not the companies intentionally making extra parts. More often than not, they were parts wh

From my understanding, a lot of that was “slippage” by employees and not the companies intentionally making extra parts. More often than not, they were parts which didn’t pass QC and rather than going through the normal process for those, they just “disappeared”, at least back in those days.