McSorely is also an accepted spelling. As a Scot, I've encountered both versions. If I remember, those Scots, of Southern Irish immigrant descent are likely to use either spelling. There are lots of spellings of common Scottish and Irish names. Growing up as a Prod., in a divided Glasgow, I only knew Paterson with one 't' - I found out, once I left my Prod. school and started work, that RCs might use Patterson. Then there's the Mac or Mc useage and Stewart or Stuart.
