My answer (the plan) is to use landau top molding. This is an aluminum base and a vinyl trim that snaps over the base. The groove is unacceptable since the base sits in the groove and the molding cannot be attached.
First you trim the top fabric below the level of the paint just outside the screws.
Next you mask a 1/2" opening from the metal edge to the fabric. Use fine line vinyl tape and 1" painters tape with the 1/4" fine line
on top of the blue on the inner and outer edges.
Using a small filler plastic, I spread the clear silicon over the painted edge/metal/fabric groove.
This is a mess! After field testing the material on the fabric and the paint to insure no reaction we are ready to begin. I used clear DEVCON home silcone adhesive #12045.
You must be fast and have plenty of paper towels as it gets all over everthing. Do 1/3 of the car at a time, 12" per pull and then get all of the related tape off in less than 8 minutes. Do the rear first. Clean-up with mineral spirits.
When you make a mistake (and you will!!) , DO NOT go back. Disregard the bad spot and come back and repair it the next day. Going back to smooth your error in more than 2 minutes and you are dealing with unmanageable sticky gummy stuff (how do I know that??????). Get the tape off NOW and you will have a clean line. Wait until you are all done and the tape will bring the silicon fillet off with it.
This step seals the groove and provides the correct base height for the aluminum. Do not be too concerned over how perfectly flat this fillet is, the aluminum base levels it as you screw it down.
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