You've fallen victim to the NOS trap. When Ford set up its service part numbers, they tried to use parts or assemblies that would be universal in application, eg, fit more than one year. If a part could be forward or backward compatible they used it. Ford was not concerned with authenticity for years, the part had to work. In your case the service part for 67 light is identified as a 68 part. If you want NOS qualiry (new), see if you can reuse the ID tags if that's what is used.
Jim