I wouldn't worry about it. Ideally it would have some very ordinary low tech oil in till about 1000 miles then change to some decent quality oil before thrashing it. I'd suggest just running it till it hits the 1000 miles and if that includes sitting unused for a while, just drain the sump into a clean tub and tip it into the tank before firing it up.
+1. Remember, oil is cheaper than an engine.
