Just found this listing on the Ottawa Co site and thought it might be of help for your visit. One more place to check out. Mitchelson Undertaking was one of the old funeral homes in that area and their records are kept at the Guilford-Thomas Funeral Home now.
Have fun on your trip, Marsha
Guilford-Thomas Funeral Home 15 A St NW Miami, Oklahoma 74354 Phone: (918) 542-5555 also has records for Mitchelson Undertaking Company of Commerce, OK