What is the value of a 1977 US dollar bill with offset margins on the back?

Answer 1

It depends on the extent of the offset. If the entire back image is visible, the bill has no added value. But if part of another bill is showing it's considered to be a sigificant alignment error; you should have it inspected by someone who specializes in error currency.

Unlike bills printed by other countries that have very strict alignment tolerances, US bills (especially older ones) can be offset by as much as a few millimeters and still pass inspection, so long as the image on each side is complete.