The calculation of the electron g-factor was carried out in 1950 by Karplus and Kroll. Seven years later, Petermann detected and corrected a serious error in the calculation of a Feynman diagram. Although it is hard to believe, neither the original calculation nor the subsequent correction was ever published. Therefore, the entire prestige of QED and the Standard Model depends on the calculation of a single Feynman diagram (IIc) that has never been published and cannot be independently verified. In this article we begin the search for any published recalculation of this Feynman diagram IIc that allows us to independently validate the theoretical calculation.