I don't know exactly when they got rid of the woodgrain panel but they kept similar controls for many years. The shape of the lid is an easy way to tell, the top also has a different shape with the sides of the top more "rolled up" than the front part (the GM 1-18 had angled sides and front but the angles were the same), the front of the cabinet also has a crease that matches the full width dryer door's lower line while the WCI has a flat front (and the WCI dryer door is slightly smaller with rounded edges).