[Ron Wood]

The fact that the toggle stays open on an empty magazine indicates that your gun does indeed have a holdopen. The serial number of your gun is low enough that it would have been manufactured without a holdopen, and one was retrofitted at a later date. You should be able to see evidence of this retrofit on the right side of the gun just below the frame rail and slightly to the rear of the trigger. You should see the head of a small pin and a very small inspector's stamp next to it.

When you open the toggle that slight amount you have moved the breechblock back far enough for the sear to engage the firing pin. That was not a design feature to allow an attempt to refire a dud, it is just the normal function of the action. It is best not to store the gun with the firing pin set, but don't pull the trigger to "snap" the firing pin. On these old guns that could lead to a broken firing pin. Either use a "snap cap" dummy round to unset the firing pin or when you have opened the toggle as you have described, hold on to the toggle knobs, pull the trigger and lower the toggle manually.

Your gun is in very nice condition and, in spite of the mismatched takedown, it is quite collectable. Do not do any refinish or restraw as this will further diminish the value. It may take a while to find a matching takedown, but that is one of the easier parts to find.

Good luck and thank you for sharing photos of your fine Luger.