I created this page on the forum, it might help you with tracking down mineral interests. https://www.mineralrightsforum.com/t/oklahoma-county-land-records-online-search/42583 Some links might be out of date.
Generally a landman can perform a title examination with good results and for less cost of having an attorney do so. One critical step is for continuity of ownership while avoiding probate generally through trusts or transfer on death deeds.