Thanks for your response. You are correct that the 1851 census with Stewart and Andrew is my family - brothers to Charles and Agnes - son to Catherine Scott Lynn. Sister Agnes marries Brisbane - have the records from Scotland People website. John Lynn is listed as deceased on Agnes's marriage certificate. The name Archibald Scott is listed on Catherine Scott Lynn Wright's death certificate (She marries Peter Wright in Scotland), but haven't seen the name used by anyone else in the family.
The information you provide from the Flaxgrowers Lists is extremely interesting and very good leads to follow. I'm 99% sure that the Lynn's were not Catholic, so it might be more difficult to find records. However, I'm going to take your advice and look into the parish areas you mention.
Thanks for the good ideas and leads!Happy New Year! Cindy