Antennae Repair? 1968 Dart

Also post a photo of the end opposite of the antenna.

I have 2 theories.

1. the antenna mast cable and all the internals are inserted into the housing and plastic is injected into it to lock it all in place. like overmolding but in reverse.
2. the antenna is roll-crimped onto the guts, then the plastic farrell is inserted on the mast and the antenna is inserted into the bottom end and pressed into place followed by a freeze plug of sorts.

your last photos make me think that theorie 1 is most correct