Norton was pretty much done by the time Cobb got around to him. A good performance by Cobb, sure, but it wasn't prime Norton.
Ive been thinking about the same thing. I know Norton was only a shell of his former self, but the 2 SD with Dokes. I haven't seen any of these fights, but I personally don't think Cobb was as bad as people say. He went into the ring and did what he needed to do, it wasn't pretty, flashy, or exciting, but a lot of times it worked. His iron jaw helped out fights like Shavers and Holmes (amount of punishment taken).
If Cobb hit a bit harder, he could have been a very good fighter. As it was, Cobb's power was only good, not great. I view Cobb as a fair talent. A fighter that could give an 80's alphabet champs a tough fight. I always wanted to see Cobb vs Douglas, as Douglas won via split decision. Was it that close? Cobb has a lot of guts and stamina. He was not an easy out. Although Cobb was not as good as Marciano or Frazier, he had some of intangibles which often came into play in the mid to late rounds.