I see a problem with your plan. Notice I said on post #5 not to use any bondo or polyester? Styrene migration is a real problem and could cause your finished parts to stick in the mold if you use bondo on the mold. If you go that route, be sure it is well covered with 2 part epoxy primer, and don't sand through the primer anywhere. I would repair the mold with filled epoxy if necessary.
Scott