They just got this and built a case for some of the Civil Wsr items of William Herbert Withington. So if the medal was not issued to him until 1890 would it still be considered a Civil War item. Although it was for bravery during the Civil War, it was probably made 25 years or longer after the Civil War.
It is claimed that Withington said it was less attractive than a Salvation Army Medal and suggested the Army redesign the Medal of Honor.
The small private museum seemed happy to have gotten the medal, but as far as I know they do not own it and it is on some type of loan. Withington was from Jackson Michigan so about 30 miles from the museum. Kind of a local boy who did well.