The bottom piece might be able to be saved, might not. You might need to do some patching there. It will definitely need more grinding/sanding.
On the back piece, either get yourself and angle die grinder with a 2" pad and go to work on that indent. Another tool that might help would be a drill with an abrasive pad that can usually be found at the local hardware store for a couple of bucks. Similar to
this style. You'll be able to get in to all kinds of corners with this type of abrasive wheel.
I don't believe epoxy likes sticking to encapsulator. And I know encapsulator doesn't like sticking to clean metal.
