I took the shelf off, and neatly covered the mirror in vintage cotton fabric, by soaking it in PVA.
A sharp blade cut the edges nearly, and also freed the centre to reflect again! I covered the top of the shelf with fabric too.
After the shelf was screwed on, gold paint was added, giving an ageing effect and helping the fabric sit well, sort of visually embedding it.
I hope Jenny likes it, do you?