Years ago, during 60's and 70's OU certified the use of peanut oil, corn oil and seeds. Miller's kimmel muenster (muenster with caraway seeds) was OU certified. I also believe that sesame candies were certified as well.
At one time, legume derivatives (oils) and seeds were not considered kitniyot for Ashkenazim. AT some point, this rule has changed.
If someone is observing kitniyot rules on Pesach, but followed the minhag based on these previous rulings for many years, can he follow these rulings now as well? Can his children or spouse follow his minhag as being the household minhag, as well?