Hi Lyn,
Actually...a Swiss metal disk, insert mag for a '24 Bern would be wrong. The '24 Bern mag is plain wood, usually not numbered (but some are with 2-digits) and have unique traits that set them off from DWM plain wood, commercial magazines.
BTW...the '24 Bern term is wrong as well...but I am just to lazy to type out "M1906 W+F" all the time...
The Swiss left a little more shape of the "knobs" along the bottom of the wood. And I think the concentric circle of each finger knob is a bit more fat is shape than DWM.
The plating on a Bern magazine tube is usually a bit more "matte" in finish as well.
I think the magazine with this auction luger might actually be a '24 Bern magazine.
I will post up photos of 3 '24 Bern magazines I own...