Sad to hear about kids. I googled the luger, since I have owned a few. Is it the Brandenburg eagle over the “M” that makes it Kriegsmarine?
Since you know your stuff then you know the proper name is the Krieghoff. And the proof mark is a crown over an ‘N’.
The ones I have are DWM, Erfurt, and Mauser variants. Various barrel lengths from 3 5/8 out to 16 inches. The extractors are all GELADEN. A couple of them have scope mounts on the side. All in European rust blue. It’s a mix of pre-WW2 and a couple pre-WW1 with the small ‘a’ under the serial number. None of them have mixed numbers between parts and magazine. None of them have spare mags.
That’s about the extent of my knowledge on these pieces. I don’t fire them. I did get myself a commercial Luger for fun and it’s nice but finicky.