Interesting, I wasn't aware that there was a GNR version of 7-30 Waters.
That does make me incorrect.
My guess was based on the .405 Win wildcat, which I now know is properly called .280 GNR.
I've heard of some of the GNRs before, but never really paid attention.
What actually got me there was that the case body and shoulder really reminded me of a couple ICL cartridges, combined with realizing that the middle cartridge in the first image was probably a .444 Marlin wildcat (and likely a JDJ).
So, I started running through TC chamberings (primarily aftermarket), looking for something with that funky, short neck.
I never did find it, but I realized that the case body seemed too long for .444 Marlin and I suspected the bullet diameter was between 6.5mm and .30 caliber.
.310 GNR popped up, and I figured I was in the right family - just with a shorter neck.
I was going to guess that it was a 6.5mm variation, but the bullet-to-body diameter ratio wasn't right and the bullets were too stubby. And the red-tipped bullet somehow looked "wrong" for a .30 caliber.
So I split the difference and went with "7mm GNR".
.375 JDJ was just a matter of being very familiar with .444 Marlin (awesome cartridge), and comparing .358 and .375 JDJ.