welcome to the forum. I am sure you are going to find that you have a very interesting luger now in your procession. I don't know a whole lot about Krieghoffs, so Im sure so others will fill you in a little better.
But as for the shape with a 2 under it is an eagle figure surmounting a numeral "2'. According to the book Im looking at it was something to do with the Luftwaffe contract. I attached a couple of pictures with the paragraph talking about the eagle over the numeral "2".
I am sure others are going to want to see some extra pictures. The top of the toggle, maybe the front of the trigger guard and barrel. They love seeing close ups of the markings, especially the one you are referring to.
As for the SN, yours being 590 and seeing the number 90 on the rest of the parts is normal. As for the magazine having a SN 8399, yeah its not matching to the gun. But from what I see in the pictures its definitely a nice piece. These particular lugers are usually on the high end when it comes to price. You can check out web sights like "simpsonsltd, legacy-collectibles and phoneixinvestmentarms to get an idea of what people are getting for them.
Enjoy your new luger and sorry to hear about your father.
