It is a Mod 39 which has an aluminum frame. The Mod 59 is the same gun with a steel frame. The SEAL's used Mod 59 pistols with KAC Hush Puppy silencers in Vietnam. Back in the 60's there was no such thing as commercial 147gr subsonic 9mm so they had to experiment with heavy bullet weights to get reliable subsonic operation and to get the pistol to cycle.
I have shot a modern KAC Hush Puppy on a modified Beretta 92 with a slide lock. That was an amazing experience. the silencer is so go that when using the slide lock, it actually holds pressure inside the barrel. After the shot you can actually hear pressurized gas leaking out of the gun and if you quickly cycle the action, there is a "pop" when the action opens. VERY COOL!
The Hush Puppy is a small coaxial suppressor with three elastomeric wipes. It is pretty low tech but it definately works.
This is a pic of a Vietnam era Mod 59 and Hush Puppy can. Note the raised sights to clear the large diameter silencer.
learn something new every day- i thought the only diff between the 39 and the 59 was trhe double cap magazine and the 59 had an aluminum frame as well- the 39 had all 3- aluminum, steel, and stainless steel
