I've just been having a look on the Latter Day Saints website and there is a record of a Thomas Luff marrying a Mary Simkins but this is in 1830, quite a few years difference from your dates.
I imagine you would know of this site but if not you go to www.familysearch.org and you can search with just the name and country or once you go into the search options such as the IGI you can then refine the search and this is where you can pick the county you want to search in.
I'll look at the names and dates you have here and see if I can link anything up. Thanks for providing them. Hopefully I will be on the site more regularly now. Good Luck. I might hear from you soon.