As you note I have posted the specific Securities and Exchange Act of 1930's and the latest amendmendts there to which in the words of an astute friend has been interpreted to affect the enforceability of patent rights as follows...

"The patents have 5 years left before they expire however there is a "look back" period of 6 years after the patents expire. EDig cannot enforce an infringement of their patents after the expiration of the patent in 5 years but have 6 years after that expiration to enforce any infringement they can find that occured before the patents life expired...."

My recollection is that when I was researching this issue i found the answers readly at WIKIPEDIA...

Gil...