456458 is your VIN since its located there. According to this VIN table, your car is a 1966 912 Karmann coupe, just like your title says!
http://www.912registry.org/restore/vin.htm
Those rear flares are odd too, good eye. This car looks like a frankenstien of different cars pieced together. I would say it was simply a '66 912 coupe front half spliced to a '69-up 911 Targa rear half, but the car still has the '68-older short wheelbase! Truly strange.
I love mystery cars like this.
