As I heard it (maybe from you?) Paul Endy himself was the "Sisk" sales rep in California at the same time as he was the owner / sales rep for Paul-son in Nevada.
Two parallel company names, with chips being designed and made in the same facilities.

Does that sound correct?

For Barry & Don -- I've got about 20 Sisk samples, including the $20 and the 2 oversize ones, but I'm missing a few of them too. Most of mine came from the Paul-son retail store as well.