G-S MX372 Watch Crystal for Gruen Curvex Crest

Found this vintage G-S Flexo watch crystal in its original paper sleeve. It's model MX372, specifically made for the Gruen Curvex 'Crest' watch. The dimensions are 24.3 x 14.3 mm. It's new old stock, so it's never been used and is ready for a restoration project. Just clearing out some old watch parts I no longer need.