Extending the height of the side of the body?

Use your prior instructions to finish the job. Add polypropylene sheets to the inside etc.etc.etc.

 

With the cove I would just add flat fiberglass to the bottom and add to the fender. Moving the trim down will mess up the swoop. Early corvettes had body below the cove so it won’t look stupid.

 

Thanks… lots to think about. Once I decide on which path to follow, l’ll post photos.