After World War One, large inventories of unused grenade bodies were sold on the commercial market. These were purchased for a variety of reasons, mostly as scrap metal. Some were purchased by novelty companies and converted into coin banks and cigarette lighters.
In this case it appears that surplus Mk.II grenades were purchased by the "Lake Erie Chemical Company, Cleveland Ohio", who were a manufacturer of riot gas devices for law enforcement agencies. Probably reloaded by them with the addition of an instruction label.
The photo of this example was submitted by an EOD group from the Netherlands, so it would appears that some were exported to Europe as well.
The U.S. military never put instructions on hand grenades, which further supports its non-military origin. Probably manufactured sometime during the 1920's.
The condition is assumed to be original.
Thanks Erik K.
EOD, The Netherlands
(and Rex for the ID information!)