If you bought it recently, you may want to be sure that you have exceptionally accurate and detailed contact information for the seller.
Personally I'd go back to the seller and try to get at minimum a price adjustment, at most a full refund on the car. Although chances are you will own the car for years and not have any issues with the documentation, what happens if you decide to sell the car?
Most DMVs will issue a new VIN and title based on a law enforcement inspection and clearance of the stamped hidden VIN. It is visible in two places, one on the cowl and one on the firewall. This would be the only legal route...but either way you will never have the same value as a properly tagged and titled '67 or '68.
Since there are four possible VIN combinations based on the partial VIN on the cowl, are you sure you submitted the correct full VIN for a LEIN check?
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching