Minister was Arthur Osborn Gibbes Alleyne who married them, was minister there from 1863
If you google the name of the church there is a link to encumbents.

If you can access the other weddings on the register it may be that the other person was a verger/parish clerk, brought in to witness when some could not read or write. signature might be better on other entries. am guessing first name Robert, and second name starts with S, and surname Ga......