You must index what is on the document, even if you suspect that there are spelling errors. I hope that you will join the group @Indexing Chat! We have nearly 1500 members now asking and answering questions and sharing stories. It is always a great find when you get to index the documents of your own family name.
I agree with @Melissa S Himes. I have family members in my tree with different spellings of their surname, sometimes because they changed the spelling due to grudges and things like that. It's just part of their story.
Spelling variations can be valuable family history clues. I know a family that knows it is their specific family line because they always use two Ts in their name and not one T that everyone else uses.