Looks like it is stamped (reading each face) 271, N, 2 IHC in circle, on sides of largest socket. Do you have this one Jimwrench(Dad)? I can't start collecting IHC stuff...
Jim
Have a pair of 271N wrenchs. Neither of them have the 2. Gil doesn't mention the 2 as a variant. Don't know the significanse of the 2.