Ahhhhh, Bummer !
Yeah, this is common amongst the EF/EL Chrome Auto Button Brigade !
Unfortunately, The AU one is different, in the sense that it uses a Hex Screw to Hold the Knob in place, where as the EF/EL is a twist on type, with a Locking nut Below the Knob, to hold it in place. (Although I am sure that this would not stop anybody from trying to fit the AU ones, especially the Momo Stitched Leather ones !)
As for repairing the Knob, I dunno if the Chrome Bit can be bought as a seperate item from ford ?
Also finally, to get a new Leather Stiched Knob with Chrome button is going to be a bit expensive to purchase from Ford.
(Not sure Exactly, but expect in the Hundreds, going by normal Ghia Part costs)
Sorry to hear about that mate !