Old Heart shaped Railroad Lock - ? Chesepeak & Ohio ?

Description

Please use your expertise on this lock.  I am guessing that it is railroad lock.  The piece that slides over the key hole has letters engraved. Looks like there is C &S and a O.   So I am not sure which railroad it is from or if a railroad for sure. It is about 3" tall if closed and 2 1/2" wide.  NO key. Shows wear as photos show.