ClassicCar

Now that the Pacemaker doors are painted, I am in the process of putting on the new weatherstrip. Most are self explanetory when you look at the weatherstrip and consult the body service manual
The one that is confusing me is the #130 style that is used for the Rear Door Rear Opening and also for the Door Opening Weatherstrip - Upper. The rubber has two perfectly flat sides (one slightly wider than then other) that meet with a 90degree sharp angle with the other face completing the "C" shape. There seems to be two possibilities for which flat side attaches to the frame with the most logical to be being that each face goes against the metal with the 90degree edge right in the back corner - the narrower one facing into the car and the wider facing the back or roof. Is this the correct way as the other way could be the wide face facing the inside and the narrow face not against anything. Does the door close against the wide edge of the "C" or against the narrow edge?
Sorry if this is confusing but someone may understand what I am getting at and be able to put me on the right track .
Thanks