Richard,
".. another reason", that of religion, disappeared on 1st July 1837, when "non-conformists" were allowed to be married in "their" church, rather than marry in an Anglican church or marry abroad. e.g. Scotland.
But your couple too young to be bothered by that.
William's "where born".
Early census enumerators were instructed to record in the "Where Born" column, either the "parish of birth" or " place of birth". Crosby-on-Eden lay between Brampton town and Carlisle, but nearer to Brampton. Scaleby lay just north-west of Brampton. So maybe his "places" were not too different !
I could not read completely his birth place on C1891 ( 4249-27-12) .. was it "Swan Hill" ??
Have you seen william on censuses prior to 1861 ? At least he has a "good" occupation- for tracing !
Michael Dixon