Bob,
Guessing a Luger's value without even seeing pictures is a hopeless endeavour. Give this a try, go to
http://forum.lugerforum.com/showthre...highlight=2104 and compare your prospective 1900 to the gun profiled there.
Although conventional wisdom has it that 1900AE are found with BUG proofs, my database suggests that they are in the minority.
The trick about operating the toggle of a 1900 is to remember that it has a toggle lock, preventing the toggle from being drawn straight up. The toggle must be pullded rearward, almost to the frame ramps, before it can be raised. The differences in the toggle knobs between the Old Model and the New Model are actually functional in this regard. The dished toggle, fluted on the front edges, is designed specifically to be pulled rearward. The checkered faces of the New Model are designed to be grasped by those faces to facilitate pulling them upward.
--Dwight