Steve rips a big piece of the truck's roof-panel upwards, yet in most of the subsequent shots, the roof is flat and apparently intact.
Actual Liberty Bell is 6 feet in diameter at widest part. This one is nowhere near that wide. It is also 3 feet high in reality.
On real Liberty Bell, Pennsylvania is spelled "Pensylvania". An acceptable spelling at the time it was made. This mock up has it spelled with 2 Ns..
Despite criminal mastermind Robert Meyer stealing the Liberty Bell in Philadelphia, he holds the Bell hostage in a box truck in an area where the background scenery is obviously mountains in California & desert terrain.