VIN plate missing rivets???

I had a 63 Dodge 330 that I purchased from the original owner. It was on a farm & owned by a nice lady. It did NOT have rivets holding the V.I.N. tag to the A pillar post. It looks like Chrysler used some other kind of way to securely fasten them on older (67 & earlier?) cars.
Thank you for the response, during the interim between me posting and just now I did decode the VIN and it does match what the car is so with your response and I'm sure a few others I will go forward with purchasing the car.