Hi..I haven't found the marriage yet..but I can confirm the baptisms of AMEY HARRISON 10.07.1803..and WILLIAM HARRISON 14.01.1807..at Horsley Derbyshire......which should mean that they married before 1803..and presumably in the area......but the Horsley marriage records do not have the marriage.....you say he retired in 1802 at the age of 48.....seems a good time to get married!!......but being 48, and with the suggestion that Catharine was a widow in 1841........seems to suggest that he might have a previous wedding somewhere..and he was a widower?..and Catherine was apparently born ireland c1769..so could have been widowed befroe she married Roger......so her maiden name may be two steps away..not one!
Later.........it looks as though Roger was a local man......I have a baptism for a ROGER HARRISON at Horsley 15.11.1755..son of John Harrison and Elizabeth nee Parker, who were married at Horsley 01.08.1755............but then again there is a Roger Harrison baptised Horsley 29.12.1755 son of Thomas Harrison and Sarah nee Stenson, who married at Derby ..neither would be a gamble on my mortgage..but......who knows...
Derek.