Since the bore is filled with concrete, it's not likely that a lot can be determined about this gun.First, a correction to the above comment. The bore is actually plugged with a piece of wood.
The bore diameter is about 3.8" and the shot stacked below are about 3.75".
The muzzle has endured some vigorous abuse with a hammer.
At
this link is a drawing from my crude measurements of this gun. The bore lines are strictly speculation as the bore is filled. If any important dimensions are missing, let me know.
Although the associated plaque says the gun was never fired, the date "July 4 1881" on the breech makes me believe it was fired during Independence Day celebrations. Never fired in anger I could believe.
You can see all my pictures at
this link.
sign says it was made by a local machinist in 1881 at the town of Bodie ... must have had a huge lathe ..STANDARD CONsolidated was a large mining/milling company in Bodie and I would expect they had some large machinery there for maintenance purposes.