I've posted in the "fakes" album a picture of a fake double struck
nickel in which the first strike looks weak and the second strike
looks like a sandwich strike.
Instead what apparently happened was that someone took an ordinary
nickel and placed a nickel planchet (or similar sized disc)
underneath the reverse. Then the two coins were compressed between
two flat plates.
While the uniface area on the reverse is somewhat convincing-looking,
the "uniface" area on the obverse is flat as a pane of glass and is
even with the flattened surface of the coin adjacent to it.
Much of the rest of the coin is flattened. The peripheral letters
and numbers are mashed down, as is Jefferson's face.
It seems that the two plates were pitted, as the flattened areas on
both faces are covered with innumerable small bumps. These resemble
the bumps on the reverse of the problematic "hex" nickel that may be
seen in the "oddball errors" album. I've sent my coin on to the
owner of the hex nickel so that he can make comparisons.