For your consideration, here is an Internationale English Metric Converter, from the Maclean-Hunter Publishing Corporation. The converter has a little wear on the edges. Item pictured is the item up for sale and comes from a non-smoking household. (49.830h-.6ob)
 

It converts on the front:

Length: Yards/Feet to Meters, Inches to Centimeters
Weight: Pounds to Kilograms, Tons to Metric Tons
Area: Square Yards to Square Meters, Square Inches to Square Centimeters
Volume: Cubic Yards to Cubic Meters, Imp. Gal./US Gal. to Liters
Temperature: Fahrenheit to Celsius

It converts on the back:

Fractional Inches to Decimal Inches to Millimeters
Inches to Centimeters
Miles to Kilometers
US Gallons to Liters
FT squared to Meters squared