Hi Matthew
At the risk of stating the obvious, firstly be SURE to reprofile/adjust the "Camera shot" flipper to eliminate airballs which cause the initial breakage. I cheated and Araldited the new Magna Flip sign back onto the bracket using the original rivet heads for appearances (nobody will ever know?)
Thanks to my mate Chillie I now have access to a rivet kit (I am too stingy to buy one) if the Araldite fails I will go this route. However the sign has sat happily for the last 4 years using the "cheat" method.
The other plastic bits issue is is a complete conundrum to me. Hope this helps.
Maxwiz