[Arran]

I would try melting the wax off of the old RF coil to see if you can find where the end may have broken off, it may take some poking around with a exacto knife or a small screwdriver to find it. If the break is on the outside you can unravel about 1/2-1 turn of it to get enough wire to reconnect it, if it broke on the inside that will be much harder. It's kind of a vulnerable spot to place such a thing so I expect it was some sort of mechanical damage rather then corrosion, perhaps when the chassis was mishandled in the past.
Regards
Arran