Snap On Impact Sockets

[SKI1019]

I picked these up last weekend. I can't find any info about them on GJ or Collecting Snap On Are they hard to find as a set? They're 1/2" drive 7/16", 1/2", 9/16", 5/8". TYIA, Steve
https://www.garagejournal.com/forum/attachment.php?attachmentid=723651&stc=1&d=1515452356

 

[snapmom]

They are old, prob. 1950s. Impact sockets. they show up on ebay every once in a while.