I went looking for John Taylor Sanderson (1839).
Found him staying with the family of John Taylor in 1851.
He is listed as a nephew.
Going to GRO I saw that his mother's maiden name was Taylor.
And then going to FreeReg I found a marriage between William Sanderson & Mary Taylor.
All of the above happens in Jarrow.
I couldn't find a connection to Isaac Sanderson despite many such people in the data.
Anyway, I think we've got the man and his family, finally.
My initial interest in Capt William (1802) was that he died in a place where I have a few clusters of DNA matches who also match known Sanderson line relatives. Not Quebec precisely but the broader region. I wanted to know if he had offspring in Canada and while we can't rule out the possibility there is no clear reason to think they existed, and I think good enough reason to believe they did not.
This means I'm ready to let go of this search if you folks are.
-DC