Hi Gregg, I have a b&w hand drawn picture representation of Robert Merrian's headstone (1782-1853) which has it spelled Merrian. The other actual photographs I have from St. Joseph's cemetery all have Marion.
I have a birth record from 1870 that's spelled Georgianna Merrian and two marriage records (civil & religious) for her in 1901 spelled Marion.
I have not seen any land records or baptism records. Many Marions are in online trees but no one documents them, as far as I can tell. I'm still working on documenting as much as I can.