Radio Antenna Replacement-1994 JGC

[JeepForever]

I'm trying to replace the stock antenna (non-motorized mast) on my 1994 Jeep GC and am having a tough time removing the nut and escutcheon on the antenna mount. I've read other posts and have figured out how to run the wires, but before I start messing with the wires I need to remove the old antenna and mounting post.

How does the top nut come off? Is it threaded like a regular nut, or is there some kind of clip locking it in. I put some penetrant on it, but when I try to turn it I see the whole bracket turning and I'd hate to break it off.

Any ideas? Thank you!

[JeepForever]

Original message: "I'm trying to replace the stock antenna (non-motorized mast) on my 1994 Jeep GC and am having a tough time removing the nut and escutcheon on the antenna mount."
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I wanted to bring this back up for discussion. My next option on removing the old antenna (nut on the mounting bracket) is to force it off with vise-grips and a cheater-bar. Or I could abandon it and drill a new hole for the new antenna. Any other ideas (I'm hoping there's a trick like "pull gently and call it nice names and it will pop right off" - I haven't tried that yet).