Aha A Courtenay Wilson birth registered Dec 1/4 1903 Plymouth reg district 5b/221 but the mother's maiden name is Williams. But he has siblings Jane c1897 Theodore 1901, Archibale c1909
A Courtney Septimus J Wilson and a Margaret Williams are on the same page of marriages FreeBMD June 1/4 1891 Plymouth reg district
If none of this relates to your Courtney and Margaret at least you can rule them out.