Need Help with this Lock

[Charles Prentice]

This lock was found detecting on the site of an old plantation home in the southeast.. The house burnt down around 1900. Does anyone have any info on what type of lock this is. A couple of years ago we found the key that we believe fits this lock. The lock is different due to the 2 bolts and the key hole Kinda cool. Any info would be appreciated..
Also any advise on cleaning this thing up...

Thanks in advance
Chuck

 

[milk86]

There is a what is it forum. Might try over there. also might want to shrink the pics as well