Well my guess is because MNII is a dilution free stock that has certified claims in Cuba. I'm sure that lawyers fought to resume trading as it wouldn't be fair for the people in the early 1900's if they didn't get their money back once claims are resolved and sanctions removed. There is a huge difference between MNII and other pink sheet stocks. Also, I have a strange feeling MNII will be reporting soon.
No one ever (in the 1970's) would have ever thought that we are as close as we are now to resolving the claims and sanctions being removed.