Bronze coated casts of Andre's hands are on display in the Adrian E. Flatt, M.D., Hand Collection at Baylor University Medical Center at Dallas in the George W. Truett Memorial Hospital lobby.
Here's a photo of Andre's cast:
Image source: http://www.juliatexas.com/hands/historichands21.jpg
There is also footage of his hand relative to other objects:
Image source: http://www.cnjradio.com/images/andre/5.jpg
Next to a visitor's hand:
Image source: http://trashcity.org/ARTICLES/pics/cac2004c.jpg
Yes, his hands were that big.
Regarding whether that is actually a 12 oz can, it is at least visually consistent with what one Ebay seller is calling a 12 oz can:
Ebay ad that says: "12oz Molson Canadian lager beer by Molson, Vancouver. 12oz Diamond lager beer by Formosa Springs, Barrie, Ontario. 12oz Red Cap Ale by Carling, Toronto & Waterloo"