Check this site to see the locations:
http://www.varietyvista.com/13%20Ei...%201971S.htmAlso note on these images of the mintmark areas, that the lower quadrant of the area inside the lower loop, has an issue with the puncheon that year.

That is not part of the RPM. That is common also on normal coins that year as well. The dies are hardened and they they use the punch on a harden die and eventually the punch bends:

Edited by coop
07/17/2019 11:58 am