Do you know when and where Beatrice died? Have you obtained a copy of his death certificate? It should show his age, where born, names of his parents etc.
Did he live long enough to apply for a Soc Sec card? You can obtain a copy of the application he filled out, and it should show the names of his parents, his residence at time of application and other data, too.
Have you found Beatrice and Nancy on any census record after they marry? Is the Nancy Clayton on TX Dth Idx and SSDI born 1881, d 1969 the wife of Beatrice?