Share 'Green felt, why?'

This may be a rookie question, but we all have to start somewhere. I have a turn of the last century guitar which is a little beaten up and has been badly repaired in the past. It has been well loved and well played but who ever mended the splits in the body and replaced the nut did it no favours at all. While IMO it is entirely rescue-able I have this to ask. The replacement nut is plastic, I in…