Has an Olympic Baseball game ever ended 7-3?
Exactly once. On September 19, 2000, Japan beat Australia 7-3, and no Olympic Baseball game before or since has ended that way. When it happened it was a scorigami, the first 7-3 in league history.
That makes 7-3 the 48th most common final score out of 87 that have ever occurred in Olympic Baseball. One point away, 8-3 has happened 3 times and 7-4 has happened 3 times.