Every original Parker Reproduction case that I've encountered has had a leather trade label glued to the inside of the case. I do not believe these leather trade labels are or have been available as an aftermarket item, so therefore; I would have to believe that if the case has an oval shaped leather trade label glued inside...is original. Incidently, there are original Parker Repro cases that accommodate 26" bbl. guns and cases 2" longer made for 28" bbl. length guns. Some 26" guns originally were equipped with cases made for 28" guns. In addition, all cases I've seen the handle is off-center to balance correctly when carrying.
Here's a link to a case for sale that I believe is an original Parker Repro case:
http://www.gunsinternational.com/Par...n_id=100091025