Well, Babbage never wanted to build the Analytical Engine, he said so explicitly. He just wanted to design it, and let someone else build it. The reason was his experience with the Difference Engine. Because the D.E. would be useful for accurate, error-free charts for the British Navy, he felt that the Government should pay for it. And he did get an agreement with the Gov, but getting the money out of them was like getting water out of a stone. He was so disgusted by the whole process, that he resolved neither to finish the D.E. nor to even start the A.E. Other than that, I think there is no question that the Analytical Engine could have been built in the 19th century.