Pushing on the hammer won't tell you anything because all Hand Ejectors have a rebounding hammer that does not go fully forward unless the trigger is pulled. The only way to tell if the block has been removed is to remove the sideplate.
The rebounding hammer was the original drop safety, but it made the gun more "drop-resistant" than intrinsically drop safe, as a sufficiently hard blow to the hammer could still cause it to fire. The hammer block was introduced after a fatal accident resulting from a revolver being dropped onto a ship deck.