In 1973, the vast Hughes empire became Summa Corporation. Source? (http://www.howardhughes.com/thhc/) Howard Hughes dot Com.
Hughes left Las Vegas in 1970 and died in 1976

But the point still stands, it says SUMMA and it was probably made as a give-away for SUMMA, not worth $85,000 for some old chips forever sealed in some cast plastic. It was made after Hughes left Las Vegas...