Fogman,
In order to extract full information value from this Forum, you ought to provide more information.
Note -all- the marks on -all- the Lugers, particularly the marks on the right receiver and under the barrel--also on the left receiver, if they exist. Serial numbers of all the guns, including script letter suffixes. Take the guns apart and note if the inside of the frames are white metal are blued, same for the S-shaped link hanging down from the rear toggle link. While you are there, make sure all the internal serial numbers match.
Note what caliber all the Lugers are--9mm or .30 Luger, also barrel lengths.
Write down the actual unit mark, be specific about where the periods are, note whether the letters are Roman or Script, and the relative sizes of the numbers.
Note how much of the original finish is left, any rust or pitting, and how much yellow color is left on the small "strawed" parts. And note how much money the owner is asking for these guns.
From your simple listing the most interesting guns on the list are the unit marked piece, the 1920/1920, and the Navy; followed by the 1915/1920 and the 1916; ending up with the 1920.
Be very sceptical about the matching mags. If you cannot find an experienced collector who can help you with the finer points of Luger magazines, actually examine them with you or for you, consider the liklihood that they are not original. Don't reject them out of hand, but don't get talked into paying a huge premium on their account.
The Navy is a special case. Navy Lugers are being actively counterfeited, so you need to know some specific information. To start with, is there a chamber date? a grip safety? is the thumb safety marked in the upper or lower position? What are the barrel and receiver marks? If you want to follow up on this gun there is much more to know. Does the magazine base for the Navy have concentric rings, and what is marked on the bottom?
Are you allowed to photograph the details of these guns?
It looks like you are being offered a pretty good opportunity, requesting the help as you have done and providing additional information to focus the help are wise moves.
--Dwight
