[lugerholsterrepair]

Todd, Your pistol was made in 1918..the 1920 is not a date but a property mark. It has quite a history. A WW1 pistol, after the war, pressed into service during the Weimar Republic era and then converted into a Police pistol and unit marked.
I assume the unit mark is either from the WW1 era or perhaps it is from the Police service it saw. I am no unit mark specialist but one will come along..Ron Smith , Don Maus perhaps George Anderson or Jan Still and explain what that is.
The 2 mags that would have been issued with this originally would have been wood bottomed, marked with the full serial number and the extra would have had a + sign to indicate the spare.
Neither of the mags you have match the pistol as you have said. The mags may have been changed during it's Police service.
Likely aluminum bottoms with the full serial # and a 2 to indicate the spare mag.

Your 42 marked eagle 655 may be an armorers replacement mag.

Jerry Burney