RE: Broken Cockpit Window, How to fix
Any way of further explaining this piece, or adding a picture?
Clear plastic can be easy to work with with a little heat. Depending on the piece you need to replicate. If there is not a lot of profile to it, a simple 'plug and mold' could be created.. a new sheet of clear plastic, warmed up and immediately pressed into the mold/plug, let cool.. and trim to shape.
You may need to play with your mold to get it right, and may burn through a few pieces of plastic before you get it right.. but that should be all fairly cheap stuff.
Without knowing what the plane is, and what piece.. thats about as much help Icould offer. Other than the manufacturer having spare parts?