This is the JR21 Dart Pistol With Periscope on its original card for the American market back ine 1960's. It was a prize in the first year of the blog and here are the happy winners back then.
Despite the guy looking like Sean Connery I've often thought the toy was inspired by the Agent 21 strip in TV21 comic. Maybe a TV21 reader could answer that?
What's for sure is that the components of the toy appeared elsewhere, notably the Agent SA17 Dart Pistol with Periscope also from the 1960's I suspect. It even has a registered design number on it but I can't quite make it out [has the Jr21 version got a registered design I wonder?]. Is this the forerunner of JR21's pistol?
The design reappeared again in 1988 with this Periscope Dart Gun by Who Doneits. Who Doneits was a trademark of Jak Pak Ltd. The history of it is online here. These are still available now as old party favours at Esnarf and MJ Variety in the USA!