Interestingly, the H C Marsh Co. Was located in Rockford, Illinois. Don't know if there was a connection to the Rockford Co.
If it were a Marples, it would have an unusual looking lever cap, and also it would have Marples cast in it. Also, the adjuster looks to be at an angle to the bed rather than parallel like the Stanley's.
There are several images of the Marples if you Google it.
Mike