1982 Large Date..seperation?

Like a very worn die. There is nothing doubled, just worn. If it were a doubled die there would be extra thickness. I don't see that on your coin.

The devices on this year look thicker than other years, but by comparing coins of the same year, you will note the same thickness.

Die wear shows on all Cents struck with worn dies. Circulation wear does not affect die wear. The example posted was an AU coin, but the die state was early in the dies life. The mark on the bottom of the L on LIBERTY only appears in the EDS examples. But the overall normal/DDO coins are affected by die states even in BU coins. Circulation wear tends to flatten devices or wear the devices down. The rim area keeps this from happening until they reach the Good grade and lower (Fair or poor) and the absence of the rim wears the devices faster. Picture die wear as a distorting of the devices making the device no longer crisp. All just part of the die life. The more die wear, the closer to retirement the die reaches.