Harmony Grove is between Fairmont and Grafton off Rt 250 on Harmony Grove Road. Area of McGee I believe that is called, before you get to Pruntytown. The only Reed there is a Addie Reed. Sorry can't help. You can get a hold of the Grafton Library. They have readings on the cemetery's probably done in the 80's but may help.
Go to find a grave site and you can get a map to simpson cemetery. http://www.findagrave.com
Let me know if you find it.