Message From Mike Diamond

I emailed Mike this morning with a few question I had. He said I could post his answers. Here is what I asked Morning Mike,
Hope all is going well with you and yours.
I have a few questions I would appreciate an answer to that has been on my mind for awhile now. In what year did over mint marks stop? In what year did over dates stop? In what year did RPMs stop? Can a copper plated cent be a lamination error? Do I,we need to be worried about catching a virus from searching coin rolls? Is it ok if I post your answers on coin Community? Thank you very much for taking the time to help us collectors.
John
Here is his answers Hi John.

There are two purported overmintmarks among 1956 cents (one is actually a misplaced S-mintmark on a 1956-D cent). However, these have been questioned. Right now the year 1955 seems to be the last definite year for OMMs. As far as I'm aware, the last year for true overdates (not Class III doubled dies) is 1909, although I vaguely recall someone telling me that they continued for a little while longer among gold coins. RPMs stopped in 1990, when the mintmark was incorporated into the master die. I've never seen a zinc cent with a lamination error, only peeling plating. While paper currency carries a large microbial load, I'm not sure about coins. Certainly any coin that has been sitting in a roll for more than a few weeks is safe. You can post on Coin Community.

Cheers,

Mike
John1