As far as I know, anything that met code when it was installed, still meets code. Even the ancient knob and tube wiring still meets code. I don't remember the exact standards, but building wiring is expected to last indefinitely. However, in the 80's the standards were toughened to give a greater margin if overloaded. The deteriorating insulation on your wiring could be a problem regardless of what code says. Likely most of the BX is inside the walls where it won't be disturbed. It could last another 48 years with no problem as long as it is left alone. It might be well to make sure it it grounded, secured to the fuse box with metal clamps. That way if the hot wire ever shorts to the metal housing, the fuse will blow before any damage is done. You should also check the outlets to make sure they are grounded. You should have continuity to the white wire and 110-120 volts to the hot wire from the frame of all the outlets. There are nifty little checkers for 3 prong outlets. Past changes could have broken the ground path.
Ripping it all out and replacing it would be a big mess. I am not sure if you could pull the BX out using it to pull newer wire in or not. Nor do I know if you could pull new wire in it like you can conduit. All electrical splices should be in an assessable box, but who know what may have been done over the last 48 years.
|