Alright, DU Essentials has all the resources necessary to make a TC. It has the RID 128 of all the resources (except the mission resource) and all the descs, #STRs, systs, spobs, ship IDs 128 and 895, and everything that's needed to run Nova without trouble. Basically, TCTC would have fit into this file in its entirety.
DU Data 1 will contain all the other descs, missions, outfits, ships, systems, spobs and eveything else that does not pertain to graphics. We may wish to split off one of the resources into its own section later on. (e.g. DU Missions 1)
DU Graphics 1 contains the rleD, PICT, spin, and shan resources. These are needed to drive the graphics for the ships, weaps, and other stuff for the TC.
Personally, I think that there's nothing more confusing than having everything in one file and having to hunt down the resources you're looking for. This way, we'll be able to look for things based on file names instead of random guessing. I'd like to point out that I gave you guys warning before splitting up the seed, so you forever held your peace when I made that particular post, apparently.
I just realized that the target and shipyard picts for the shuttle ought to be included in the Essentials file, as well as the Earth landing scene. Unless people have already started moving things around, I'll have to put that on my to-do list of minor fixes.