You forgot about the Loki! Also, you might even be able to add in the Railgun as a bonus weapon... perhaps available to resourceful players. Now, I don't know what the plot is for Awakenings, but here's a possible example. If there happens to be a cargo depot nearby, either controlled previously by the GTI or HoL, have one of the containers have the Railgun prototypes. If the player decides to scan these cargo modules out of curiosity and scans the module with the weapons, the option for the player to call in a freighter is added to the reinforcements list... no messages telling the player to call it in, just slip it in there. The freighter's available commands would include "capture my target" and should the player order the freighter to capture (dock with) the module with the weaponry, then tell the freighter to jump out, the "add-weapon" sexp would make the Railgun available... no changes to the debrief. Maybe this is too much to integrate or too much to change, but it'd be a cool way to hide easter eggs.
Later!