Mineral Deed and Ratification of Oil and Gas Lease from 1950"s

My parents, now deceased, acquired a percentage of mineral rights for a section of land in Mountrail County. The deed itself shows one section. Along with the deed, there is a Ratification of Oil and Gas Lease from Company A. This ratification added two additional sections. This took place in the 1950’s. In 2005, company B purchased a 5 year lease on only the original section. In 2012 company C purchased the lease, drilled, and started pumping oil on the original section. I have been receiving regular checks from company C.
My question is: Do I still have rights to the two additional sections listed in the Ratification of Oil and Gas Lease? There are active wells on both sections.