Perhaps I am missing something, but I see gamma terms in the definition of the Labor (L) aggregate at the bottom of page 33 in the Introduction of OLG Models document, and definitions, but no uses of gamma1 and/or gamma2 for married couples in the code.
I note that OLGModel12 does not use gamma at all, despite referencing it on the bottom of Page 31. I’m going to try correcting OLGModel12_ReturnFn.m and kill two birds with one stone.