1958 Zenith Deluxe 500 Radio Issues

[vortalexfan]

Hello everyone, a couple of years ago I bought at a local antique mall a 1958 Zenith Royal Deluxe 500 Radio that when I got it one of the battery terminals inside was corroded so badly that it broke off from the battery compartment but it still worked if I set the terminal up against where it was originally set and hold it in place with the battery.

Anyways I was trying to do an alignment of the radio and I was trying to adjust the IF Transformers (it has 3 IF stages) and the 1st IF stage has two IF Transformers a Primary and a Secondary.
When I was trying to adjust the secondary transformer I accidentally broke the slug (or at least I think its broken as it refuses to turn using a smaller sized screwdriver), how do I go about repairing one of those broken IF Transformers?

And also I've tried using this radio at work to listen to some of my faivorite stations on the AM Band and for some reason or another the AM Band is completely dead on the radio all I hear is static and various noises that sound like a signal generator test tone at various spots on the dial, I can even hear the music that is being played on the sound system at my work over my radio at around the 900 kHz mark on the dial, which is weird because as far as I know their sound system is of the hardwired variety complete with wall panels for controlling the sound system in the various sections of the restaurant.

So my question is, how on earth would a hardwired sound system be able to transmit sound onto a radio without some sort of low power radio transmitter?
Also What would the restauarant I work at have electronics wise that would more or less jam the entire AM Band on a battery powered AM Radio?
I know security systems interfere with FM Signals and so do Florescent lighs with electronic ballasts, but I've never heard of any of those things interfering with the AM Band to the point of completely disabling the AM Band.

Any Ideas as to what might be going on with my radio or at my work that would make it so that a radio of any sort is basically useless there?

Thanks for your help.