The VIN you should be looking at is the VIN on the fender in the engine compartment. Not the door. If it is a 68, it should be in the front windshield, drivers side. You should be able to see it outside the car.
Are you sure you have a 67? Could the mistake be a typo in the year and not the engine code?
Mine's a 67 and and i967mustang has a picture of his 68. The easiest way to tell them apart is to look at the side marked lights in the front and rear....the 67 does not have them.
Hope this helps
68 GT Vert - J Code (1st car I ever drove in '73, dad bought it in '71)
67 C Code Vert Sports Sprint (1st car I ever bought in '75)
06 Vista Blue with Pony Package (1st Mustang I ever bought new)
MCA #49294 Grayson, GA (Atlanta)