Just wondering what the difference between early and late are?

I guess the muzzle brake is the most visible difference :

Early "slotted" muzzle brake :



Late "double-baffle" muzzle brake :



IIRC, the late variant has a new square central base plate, and a new towing lunette assembly...

HTH

Frenchy

Yes, the most significant difference is the muzzle-brake and its towing-assembly.
I also have a photo of Trumpeter´s versions, showing the "early" (now released) and "late" ones.

Also the Skif-kit of this howitzer has a rectangular-base and the "late" muzzle-brake.
I built it some years ago.

greetings...
Soeren

PS: The upper photo looks as an combined HDR-photo... to me.
It looks very good and shows the high contrast.
I also try to make photos with this technique and some other, to make "color"-photos using 3 or 4 black/white photos, for example. ;-)

Yes, dear friends, You have noticed good differences between different versions of D-30.

One more difference for You:
- earlier howitzers had the road wheels with 8 lightening holes each (these wheels were from ZiS-150/ZiL-164 truck family):



On Your previous images in this thread We can see the road wheels with 4 holes each. These wheels (of same size) are from ZiL-130 truck, which was the descendant of ZiS-150/ZiL-164 truck family.

And tyre's tread patterns could to be different, of course.