woah, 1 thing that just jumps ut at me is that youre using the P40 to hold the screen in place. not the best idea at all. you need to secure the screen 1st - epoxy, hotglue etc etc
Filler is just for, well, filling! it isnt meant to be load bearing in any way - or else it will crack and go ****e after a while. gonna look great when finished though gj!