I'd stop right now and dial the phone (if ViewCamera Store has a phone number) if I were you. What you read on ViewCamera store can be read etiehr way. If the focus panel was designed with a recess for fresnel under the GG then it seems like Rudolf could be right. If not, then Dan could be right.
And AGx is right, too. A Fresnel is optically about 2/3 it's physical thickness. I do not use a Fresnel on either of my view cameras for this and other reasons.