If the tackle box is 11", I doudt the fish weighs 1#. If it was 15" or more you would be in the ballpark. Still nice fish if you like rock bass.
Around 14 inches and very thick will be close to 2# in weight. I've caught my personal best rock bass at 14 inches. I didn't have a fish weight scale at that time, but mine was kind of more elongated, than thick and fat.
Still a 12 inches rock bass is a nice and very respectable size. I typically only catch them under 7 inches, fat and stubby, big bulbous red eyes.