Connie Lenzen gives some good advice today for genealogists eager to "correct" their ancestors' mistakes: Leave 'em be.
The spelling and punctuation quirks give us a sense of the times when our ancestor was living and when Standard English was different than it is now.
Besides, we may make dreadful errors if we insert commas where they shouldn't be. The ancestor whose will says, "And I leave to my derely belovd children viz: anna mariah jane martha john hennery mary louizer and stephen " did not have nine children. He had five: Anna Mariah, Jane Martha, John Henery, Mary Louizer/Louisa, and Stephen. [Link]