Help needed! Western Field shotgun

A very good friend was gifted a Western Field 20 gauge bolt action shotgun. The finish is in good/great condition as is the stock however it is missing the magazine. I have been all over the place looking for this seemingly fictional part. The gun is actually a Western Field 15k, I'm finding some resources say this is a Kessler 128FR and some say its a Mossberg model 80. Can anyone put some light on this and further can a magazine be had. gunspartcorp seemed to be the only place that EVER had the mags to the Kessler and they've been sold out since 2010 apparently. I leave this issue in the hands of you gurus

Pic of gun in question



Hope this helps, not the best photo but what I had right now

His father is who gave it to him and he's a yankee trader, the gun came to him with no mag and he's had it sitting in the safe for years. The issue we were having was the "K" after the 15 which seemed to cause some model variance. I will relay to him that most agree its a mossberg. Which is far better than it being the Kessler.