Sillgen: Thanks so much, I didn't realize that service was available. Turns out there is an LDS Family Histories Centre on my street here in Canada!!! I will contact them to see what they offer and how to access the service.
Trancesgirl: Yes that is an option I have been considering. The problemis that I have paid for and ordered several certificates in the past and they were pretty much useless. They should have had place of birth, parents' names etc. Yet they only had the names of the two people married and the date of marriage and on the death certificate... nothing about where they were from or parentage etc. It was an expensive lesson. So, if I can find information via other routes I will try that first. If not, I will go the "ordering of paperwork" route. Thanks for the info on ordering via the Chippenham Record Office, that sounds helpful.