Just been looking at Gt Mongham parish records and they are, sadly, incomplete. The marriages for the period in question are not there but the Banns are and they show what you already know, that Charles Lawrence maries Elizabeth Hammond, Widow on 18th Sept 1877. There were the customary three sets of Banns and a note saying they were married on that date. Unfortunately no clue as to Charles' father.
Regards
AJ