Hello Barbara
The Neil and Mary McNeil that you refer to in your post i believe maybe my gggg-grandparents? In the 1841 Census in Piperhall living next door to Neil & Mary are my ggg-grandmother who is Jean McNeil and my gg grandfather Daniel, my ggg-grandfather Richard was not at home at the time of the census, but i can confirm that his parents were a Neil McNiel and Mary McNiel from his OPR birth record in 1814. I have always thought it strange that my ggg-grandfather Richard was an only child, so i would be very interested in anything which could confirm or deny that this Neil and Mary in Piperhall are related, and throw light on any siblings of Richard.
Looking forward to hearing from you. hopefully it is a match and we can share information.