Vintage / antique WW2 Paul Weyersberg "take down" gravity knife. 
 
We believe this to be the second pattern as it is it can be broken down for ease of cleaning in the field.  Made of wood and carbon steel.  
 
These were given to Germany paratroopers.  The bail was meant to hang from a strap or belt.  The design was meant to function with only one hand.  The blade was for cutting parachute straps if hung up in a tree.  The marlin spike was to help untie knots.
 
-To activate the blade you simply move the lever forward with your thumb and turn knife blade side down.  The blade then slides out.  Once out you move the lever back in its back position to lock.  You perform the reverse to place the blade back inside the handle.  The marlin spike simply rotates out like most jack knives. 
 
-To break down the knife you push the square button.  Once the button is pushed the top guard slides off.  Once this has been completed you rotate the scale to one side exposing the blade.  The blade can be simply removed at that time.
 
6" long when closed and 10 1/2" long not including the bail when open.
 
Markings found match and are "253".  No other markings found.
 
Fantastic condition for its age.  Functions as it should.
 
Location D2