I contacted Cobra Restorers regarding the different mouth form. I also found on the catalog, they sent me with the order, that there exists a front and a rear version. For my opinion they sent me the wrong version!
The answer I received on this points:
Mouth: the original cooling ducts where made by hand. They never looked equal!!
Wrong item: you should order the other one!!
Bruce (or somebody)
Please send me the phone-, fax number ,post- or e-mail address from Bill Kemper.
I'll contact him and ORDER the parts from him!!!
ALF