Technically, for a mechanic or repair station to sign off a continental engine as an overhaul you have to comply with the provisions of Continental Service Bulletin SB97-6. Otherwise its a big IRAN, Inspect and Repair As Necessary.

http://www.tcmlink.com/pdf2/SB97-6.pdf

Charles

Visit my Early Cessna150 website

http://150cessna.tripod.com