With a Standard Airworthiness certificate aircraft, Turbomeca AD or CN 2001-445A the 1800 hours TBO time was dropped down the TBO to 720 hours or 15 years since overhaul for Marbore II engines
and 1000 hours TBO or 15 years since the overhaul for Marbore VI engines.
Be carefull, you could be flying on a non airworthy aircraft.