Different makers. The cartridge used is the 9x19.
39 holds less rounds then the 59
Basically, nothing.
The markings.
Size.
That will depend on what are you comparing it to.
An engineering change.
No tirggerguard screw is the main one.
The 9mm Lugar round is longer than a .380 Caliber, which is also equal to 9mm in diameter. The overall cartridge and the bullet is larger and the case contains more powder. The 9mm Lugar is more powerful. BTW, the .40 cal Smith and Wesson is also called a 10mm. It is only 1mm larger in diameter and a little more powerful than a 9mm Lugar.
One is blue and one is stainless steel
908 - Black finish 3914 - Blue finish
The one screw basically.
52-1, single action only.