Are These Real Experimental Coins

At first I thought they looked like Gallery Mint uniface copies. But now I think they are presentation pieces from a generic replica rarity coin set. The bubbly and rough surface make me think they are silver plated base metal.

Regardless how accurate this assessment is, they are not from the U.S. Mint.

They aren't from 1796 or 1916. The fact that they have identical reverses, despite being purportedly over 100 years apart, clearly indicates they were made at the same time and place - presumably, as noted by others above, as part of some kind of replica set. And made some time after 1916, once that date of SLQ became somewhat notorious.

I would also presume the set dates from prior to 1973, when COPY stamped onto replicas became compulsory. I believe Becker Reproductions (Peter Rosa) made and sold such items back in the 1960s.

Agreed.