An Iver Johnson revolver would have had a firing pin as it came from the factory, yes. It would be mounted in the frame rather than on the hammer, because Iver Johnson invented the "transfer bar" safety device, which requires the pin to be frame-mounted to work.
Iver Johnson made decent guns for a modest price for many years. They are not Colts or S&Ws in quality of workmanship or materials, any more than a Model T Ford was a Cadillac or a Packard. These guns were made for short range self defense, rather than target shooting (unless you've got something unusual).
I am not a gunsmith, but the most basic things to look for would be whether the cylinders are lining up with the barrel properly and whether the cylinder is locked in position fairly tightly when the trigger is pulled back for firing. The top catch was another weak point - it should be snug and not loose when the gun is closed.