How do you open a Viking 67-S .22 Cal. Revolver?

If your revolver is an Iver Johnson Viking, it is a top break revolver. Holding the revolver in your right hand (finger OFF the trigger) use thumb and forefinger of left hand to grasp barrel latch (between back of cylinder and hammer) lift the latch, and revolver breaks open. If this does not work, take it to a gunsmith.