Lots of Pics of Thompsons during Vietnam war years... VC, NVA, US, ARVN etc. What is trending, regardless of possessor, half of the pics are stockless Thompsons. The Hand Grenade in question (unknown time frame of this photo) ... is more than likely a VC / NVA small factory (some say homemade or improvised) hand grenade captured from enemy cache or soldier, these varieties usually have a very short wooden handle. Probably utilizing captured ordnance to augment their own short supply, just an educated guess. Really great photo.