Not so sure about the bit about "...Lockheed's response to the C-27 Spartan". After all, originally (after the joint Lockheed Martin Alenia Tactical Transport Systems (LMATTS) partnership ended), Lockheed offered the basic C-130J for the same role. Also given that one of the reasons for the recent USAF C-27J cancellation was that the C-130Js were already being used in that tactical transport role, there would be no need to develop a whole new response. Rather, this is more Lockheed Martin squeezing more possible sales out of the old girl...especially for possible customers that don.t want to (or can't afford) new build C-130Js...not that that is a problem.
Similarly, the SC-130J is nothing new - I remember being briefed on this concept by Lockheed Martin back in the '90s when I was with P-3s in the RAAF (this was pre- P-8/BAMMS etc). I am sure it was also mooted with earlier variants too.
Anyway, not that any of that really matters. What is interesting (to me at least) is the new tail fin and winglets and nose proposed for the C-130NG announced at the same time as this. Makes for a bit more of a modelling challenge if one is going for total accuracy.