Timepiece Service Center

This stuff is the key its called PolyWatch see https://www.watchobsession.co.uk/products/polywatch-acrylic-glass-scratch-remover we keep it all the time and it works really well. Toothpaste is potentially a quick fix if the scratches not too bad but I would look at using PolyWatch if there's no actual physical damage to the crystal alternatively we can probably replace it but nine times out of ten Poly does the trick.