Burgo 'protective pen gun'

Hello

I am posting this request on behalf of friends who have come upon a pen gun made by Burgo that they are trying to find more information about. The pen is in a beige box that says "protective ball pen", and included was a slip a paper that says it's 320 Spec 38 Spec, and the following instructions :

When loading or unloading, be sure to keep trigger in the first Safety-Notch. To load, unscrew Charging Cap, insert shell, then replace the charging cap. To fire, pull trigger back to second safety notch, engage, then snap-off trigger with thumb.

The pen itself says Burgo on it, and Germany (and since it's all in English I was assuming it was made there for export to the US)

Thanks very much

Bill