So I've actually converted this mod already http://www.nexusmods.com/fallout3/mods/15135/?, fixes included. The problem is, it messes with some Rivet City NPCs for some reason. A whole bunch of them don't move from the entrance of Rivet City, right at the bridge, instead of following their routine.
When I deactivate the Alpha Cev esp, they immediately dissipate and return to their normal routines.
I can upload the file, but I imagine anyone interested in investigating might want to just convert the mod themselves instead of trusting a novice's work.
If you have any idea what might be causing this but don't feel like testing, please don't hesitate to share your insights anyway.
As far as I'm aware the mod only changes the RCupperdeck cell. There is an image on the nexus page with directions to the apartment to give you an idea of where it was added. When entering the upper deck as demonstrated in the image and reaching the end of the hallway, ordinarily there would be a dead end on the left with some destroyed shelves and clutter. The mod adds a small section of hallway with a shelf that has the key, and a room with an elevator to the apartment.
