At first, I wasn't planning on responding, because I only remembered my relatives using pagers in the 90s, not 80s, and I didn't think my information would be much help, (especially after I read Wikipedia's page about all the different types of pagers that existed and still are in use, today), but since others responded how their pagers worked, which was exactly how I remember my relatives' pagers working, I thought it might be useful confirmation.
I only remember that my relatives' pagers would beep and their co-workers' number would appear, to let them know they had to call back, immediately, from a landline phone. They recognized most, if not, all of the numbers of their co-workers, so they knew who was calling them, even if their pagers didn't have their co-workers' names attached to the number.
I'm unsure what your 911 message added to the end would mean, whether your cop is just trying to tell the FBI agent that he wants her to call him back, immediately, because it's an emergency or whether he wants her to call 911, in addition to calling him back? If it's only the former, as a way for her to know it's an emergency, I'm not sure whether that's needed, because my relatives always knew that, when their beepers went off, obviously, their co-workers were calling them because they needed them for an emergency at work; I don't remember them adding 911 to their calls, but of course, for their jobs, they weren't cops or hospital workers, so they didn't ever need for anyone to call 911, only for communication between them and their bosses/co-workers. So, perhaps, people who worked in those fields back then, had a different protocol.