History of the Sealtest Foods Division of National Dairy Products Corporation and the depression years

I think it's about Sealtest Dairy Company, founded by Vernon F. Hovey, taken over by his 2 sons. In time, it became a division of National Dairy, along with KRAFT Foods Sold off several times, ending up with a Canada based company. From there I've lost track. The company's catchphrase was "Get the best. Get Sealtest." They had the WORLD'S BEST ICE CREAM, even had parlors at Disneyland.