Donna,
I cannot explain the two different enlistment dates. However, I believe they are one and the same.
As to "on picket at Bambridge Ferry. Order of General Lee(returned)" He was recorded on this muster roll as absent, on
picket, etc. The statement, "returned" is a notation made sometime after the muster was taken that he had returned to his place with the company, i.e., "off picket."