I have set aside the old cowls for now and today started trying to get the new ones to fit. I trimmed 50-70mm from their aft edges as they were way too long and as they are so stiff, I needed to trim the lower cowl in the area of the nose landing gear mount. The support bracket that rivets to that mount will not fit at the moment and the cowl is resting against the heater shroud. Now the extreme excess length is gone, I'll be able to use the edge finding tool & trim them to the correct length that will hopefully provide a bit more give, allowing the bottom cowl to be more conforming.