Hi Silvereagle29,
I think you may be confusing the pictures of my mag with the serial number of the K date that Don H is considering buying. He has not posted the serial number of that gun yet and has posted no pictures.
My 321 mag is likely the same you are referring to. I purchased it from the a fellow in Iowa who was the son of the gentlemen I believe you are referring to. I know that he lived in CA.
I also bought another S coded mag, several other miscellaneous mags, a G date P.08 with 2 matching mags that came with a 1935 military holster and a pressed paper P.08 police holster. Click on the link to see the holster, if you care to. I have links on that page to a couple of other paper items I have.
http://lmd-militaria.com/page164.html
Regards, Leon