Power Antenna Replacement

Hi, Has anyone ever replaced the power antenna on a Pace Car? On the one I have, someone bent the antenna years ago and the previous owner disconnected it from the power source rather than replace it. Now, I'm trying to figure out if I should order the entire power antenna assembly or if just a replacement mast can be installed to save money. I hate the thought of having to disassemble the left rear exhaust anyway, but when I do, I'd like to avoid making any mistakes.

Thanks!
Franc