This is just one of the many differences between a 67 and a 68.
The handles are not interchangeable...the stainless glass trim is different. Only the glass is interchangeable but as John mentioned, the glass will have a date code. Clearly, somebody changed either the vent assembly or perhaps the door.
A person can make a part "fit" many different ways (when building a project) but not dealing with the nuances that differ, doesn't bode well on a Concours show field.