AKSledhead,

You're right, "fat" in those days was reserved for "Fat Albert," the C-5A, not for the B-52. The C-5 was fat compared to  other aircraft in the inventory.  While I was on active duty in  the AF an order went out that active duty personnel should not use the rubric "Fat Albert" because (higher command believed) that was a "pejorative connotation of the aircraft."  Of course, we continued to call it Fat Albert, and the B-52 was BUF.  I think the second F was added for spelling reasons but not by those of us who used the term.