Not to discount the other guys but try the automotive GOP.My brother got me onto it,he had his own body shop and told me about the stuff.He swore by it,I tried it and now I swear by the stuff.Theres also some stuff called Quick Steel.Its a two colored putty that comes in one roll.slice off a piece and kneed it together,you have a few minutes to get the pieces together.sticks to anything and cures underwater.It will stick to glass and stay there despite the temperature,theres a piece on a window pane in my brothers garage,been there four years.after its cured,you can file it,drill it,tap it,sand it.Try different things until you find what works best and looks best at the end result.