Ive been looking around for this npc today, and can't seem to find it. It was the vendor that had all the mark XII Equipment and such, that you used to buy with emblems. It used to be in the central core, where did they move it too?
they actually split it up into a space vendor and a ground vendor, and the new vendors are now located right next to the existing EC vendors for their type of gear. So as stated above, the Space Dilithium Vendor is in the ship requisitions level of the shipyard and the Ground Dilithium vendor is in Requisitions on the main level, in the corner by the gun rack
Urgh, it's no wonder people never know where to find anything in this game - it all changes from time to time, just as you start to learn where everything is.
Personally, I've never really learned where anything is. Although it makes sense to have things like a vendor selling ship items in the actual shipyard, but I wish Cryptic would devise a standard set of rules for where various mission/vendor NPC's are, and then explain those rules to players. That way, even if we don't know from memory where something is, we can figure it out.