The old TCM bulletin had this:
Thousands of hours of operating experience indicate that Teledyne Continental Motors (TCM) aircraft engines, when operated within prescribed limitations, instructions and recommendations, can be operated between overhauls for the number of hours listed in the following table. The overhaul periods listed are recommendations only. They are predicated on the use of genuine TCM parts, compliance with all applicable Service Bulletins and ADs, as well as all required preventive maintenance, periodic inspections, manufacturer's specifications, and the determination by a qualified mechanic that the engine is operating normally and is airworthy. The accomplishment of cylinder leakage checks and spectrographic oil analysis may be helpful in making this determination. Any operation beyond these periods is at the operator's discretion and should be based on the inspecting mechanic's evaluation of engine condition and operating environment. Calendar time also affects this condition and should be taken into account.
The latest copy does not have the statement "The overhaul periods listed are recommendations only".
http://www.proaeroengines.com/docs/FCD65C1569DBB26D.pdf
I also cannot find any reference to commercial or private use of the engines. I think it might be hard in a court of law to prove to a judge that it is OK to fly an engine over TBO because it was for private use, particularly if someone had been killed or hurt due to an engine problem.
I have not checked, but I was told Lycoming still has a statement that TBO is a recommendation only, so maybe that type of engine can still be run past TBO.
I personally run a Lycoming in an experimental airplane, it has 500 hours since TBO in 1981 so it is overdue on calendar but since it is in an experimental airplane I don't have to comply with the TBO rules. It is also not insured! I try to avoid any congested areas and fly only over places I can set down without any collateral damage. It has wheels and floats so I have some choices in that regard, but it does worry me a little. In the US litigation can make one a pauper and I would hate to leave my family destitute just because I like to fly.