Your surname, like my St. Onge, came closer to the real thing as the decades went on and people became more literate.
I have found my St. Onge not only and Santo, Santon, and Santois, but Santay and even Sententos!! Even Centaue!! I never once found them as St.Onge in the census until 1920, and then only a few.
Unfortunately the idexes don't always correspond with the actual image either...and ancestry lists them the way the index is.
I usually just go "sant*" and look at everyone....I sure would have millsed alot of people if I hadn't.
Also, I have found the "Sants..." indexed as "Lants..." because the S looks like an L until closer examination. So I would even suggest to the Santimaw researchers that you look for "Lantimo" etc. and even "Lamtimaw"...since that n is sometimes indexed as an "n".
Happy tree building!!