Hi Chris. Who exactly are you looking for in Swansea St;Mary's? As I have these registers on Microfiche.. Ive got them from 1631 to 1837 covering Baptisms,Marriages,and Burials.   Then on another Fiche I have the 1838 to 1900. But these are for Baptisms and Burials only.   You would have to get any post 1837 Marriages from their local register office.   Please notice if you have any lookups in mind in the future folks, Do not forget the "All Wales Lookup exchange". Click on the county to see who holds what?   My stuff is mostly for Glamorganshire. Although I have some for Carmarthenshire.   HTH;Cheers Graham. Graham Williams, Glam;FHS# 551. of Canton,Cardiff.