These two catalog pages describe an undisclosed year of the product range from MDI. These models are:
Bicycle Pump Heads or "Adaptor"s
If you were lost before and looking for answers about your MDI pump this should help a bit.
1 - 1/4 " leather pump washer dimensions (Top Super, Cyclepro, likely others):
2.4mm (3/32") thick, approximately 30 degree cut on radius (angle cut on outside of leather - not the angle of the outside of the cup)
9.5mm (3/8") center hole
9.5mm (3/8") height
27.8mm outside diameter at top (1-3/32")
31.75mm outside diameter at base (open end) (1-1/4")
(28.6mm or 1-1/8" inside diameter pump tube)
Image is from Monarch-McLaren, Ltd. This is not a drawing representing the MDI pump washer but it will help interpret the given dimensions.