Vintage Cars: VIN Number, 1976 corvette stingray, digit format

Question
I'm looking for history on a 1976 Corvette Stingray. The VIN number has only 13 characters.(Original VIN)
I checked and wrote it down my self.

Is this normal or am I missing something?

Answer
The current 17-digit VIN format went into effect in 1979; previous to that it was 13 digits, at least back to the 50s.  Unfortunately, any records that you can find online are for vehicles with a 17-digit format (at least I've never been able to find records for pre-1979 vehicles).