Hi Anmac11,
John Fraser 1799-1866 was my 3rd great grandfather. I have limited information about the family in Scotland, but know that his parents were Simon Fraser and Margaret Macintosh, just as you said.
The details of their date of marriage are also correct. I am not entirely sure of the names of John's siblings. You have said that they were Margaret, Isabel, Mary and Thomas. One of my contacts says they were Simon 1801, Margaret 1808 and Hugh 1814. John Fraser was a missionary and school teacher. I have been told that we travelled out to Boreray with his wife Jannet Mackenzie, who helped him with teaching. You refer to him as Rev. John Fraser. I have never seen him referred to with that title. The link to Dunain, with his father being a tenant is also correct. I know nothing about the croft name you referred to of Tom a' Mhoid, but would be interested to know more if it is linked to my family. I have a family tree on ancestry.com. I live in Australia, as John Fraser's grandson, Simon, emigrated in the late 1800's.
regards,
Jane