Snapo Hand Tool no.72 <> Pop Rivet Gun ?

I am having trouble identifying this item. It has "Snapo no.72" on one side,and "Richline Tool Co" on the other side. Some people say that it could be some kind of spark plug wrench,but mot say it could be a hand held Rivet Gun of some sorts. I hope someone on Collectors has and idea of exactly what this item is. Thanks for your help !