My friend has his grate grate grandfaters Enfield from the Civil War. But it has strange barrel proof markings.

1853 Enfield 58 Caliber ss

I know the ss stands for a company but which one?

This is all the information I have because the weapon is in bad shape. Before he got it, it was left out in a barn. The stock, hammer and hammer housing/hammer lock is missing.

I am would like to find a stock drawing so I can build it myself for him. I think he would like that better than just buying him one.

Any information would be a grate help.

Thank You.