Vintage Keuffel & Esser Co NY Compass

This is a vintage Keuffel & Esser Co New York 45.7 mm wide compass.The compass appears to work fine.The front lever and spring work fine.The face looks in nice shape but the crystal is spotty.I tried to wipe it off but it appears the spots are on the inside of the crystal.If someone has the confidence to remove the crystal and clean it off you could get a good deal.Although it doesn't look too bad the way it is.