I have a lincoln wheat cent from the teens where the front and reverse are not completely upside down from each other. If you look at the front evenly and flip the coin over the reverse is apapprox 25 to 30 degrees off from the usual upside down that coins are from the obverse. Is there a technical name for this. Sorry I don't know much about error coins. Is this unusual for early wheats. Ill see if I can upload a pic when I have a chance.
Any Rotation under 15 degrees is considered to be common and doesn't add value. I use a coin flip to guage degree, on one side I mark it every 15 degrees. You'd probably be surprised to learn that a relatively high percentage of coins have 5 to 10 degree rotations! Hope this helps.
It's called a "Rotated Die Strike". Any rotation less than 15 degrees doesn't add value. 15 to 45 degree rotations add some, but not a lot, of value.