the eyes might work, but that wouldn't beat ultron i don't think, just blind him. the vision down the throat would be contained by his indestructable body -- it would have no where to go but inside and destroy whatever is in there . . . and he's been defeated by having his innards scrambled a couple times at least.
Superman.
Smashing Ultron is a "top level" feat for Wondy, and he cant do it consistant'ly or often. He doesn't break the Adamantium, but rattles him so hard that he sort of falls apart from the inside, where he's made of softer stuff. I have no doubt that Supes could do the same, and probably more easily. I think Thor did in a couple of the Adamantium Ultron's in Slorenia as well, but I'm not certain, I havent read those in a while.