Well, it's a twin that burns 11.5 gallons per side at 65% power, and gives you 165 knots at 8000. Doesn't sound like a seminole to me, but perhaps an early model, or an early Seneca?
One wouldn't expect a single to have a column that reads "fuel flow per engine".I'm probably going to kick myself, but how do you know it's a twin?
With that hint from Ted - we should look for airplane families that use one engine in a single, and two of the same engine in a twin version.... Comanche comes to mind, maybe a Bonanza/Twin Bonanza (as a WAG)?
It may not even be for an actual plane...