Murmansk wrote:
I've damaged my fibreglass bath by dropping a heavy glass shower
screen onto it.

This photo shows the damage

https://www.dropbox.com/s/a07wjnz8hl...55.16.jpg?dl=0

I'm wondering how best to repair it - my first thought is car body
filler?

Accidental damage is cheap on house insurance.
Or did you not bother?