Buy but only at a roller price. You have to assume the worst case and that is engine replacement. Maybe best case you can get away with less but why risk it? You won't know its true condition until the engine is out and lots of hours are invested and tests are made. Plan to replace and rebuild the engine you took out and resell that to recoup some of the costs?

The M96 isn't American iron where you can find an engine in reasonable condition in a junk yard for $1500 worst case or get a long block rebuilt for a bit more.