"I am the original owner of the car and I feel not having the MB star in the windshield possibly affects the reasle value."

I believe the resale value of your car already took a hit by having to have the windshield replaced. I seriously doubt that not having all OEM parts will affect resale value unless that's a 300SL Gullwing sitting in your garage.

Sekurit and PPG windshields are excellent quality replacements so long as they are properly installed and sealed. Applying some form of sealer over the old does not sound kosher to me.