Accura Precision Muzzle Stabilizer

[Bobba]

It being over 20 years since her father died, my daughter-in-law was rummaging through his strong box in the attic and found these. (He was a Senior Army Officer who took an interest in Armament improvements).

The leaflet is self explanatory. But are there any PW members with personal knowledge of these items? Did they actually come into use, for example.

Of particular interest would be advice from this knowledgeable community as to the legality of their retention by my daughter-in-law. Thanks.