I just saw your post today. I think your best bet would be church records belonging to the denomination that your people would have married. I think, given the info you provided a search of the marriage records for the Anglican church would be your first port of call. I do not know how far their records go back or what state they are in, but I suspect that a marriage in Port of Spain would be the most efficient start. You may also be able to utilize their marriage banns book if there is one dating from that period.
I would also suggest that you go to Google books and search for the name of the groom. If he was of sufficient rank, or his bride from a family of some social stature, their marriage would have been noted by a periodical of the day, along with other pieces of information that may come in handy. That's all I can think of for now; I hope this helps.
Joanne