The antique gumball machine that Al buys is said to be 75 years old, but the style appears to be from the 1920's-1930's (or later), only 30-40 years from the show setting (early 60's). But even if the machine was 75 years old, the gumballs inside couldn't have been that old as gumballs were invented around 1907, only about 55 years before.