On my KZ the washers were missing on the elevating shaft, the boot was crooked, the putty tape under the base was decomposing and the sealant didn't adhere at all to the base. Two screws were stripped.
Water was standing under and corroding the base.
I replaced the shaft and all small parts.
I used silicone on the cable under a new boot.
I used butyl tape under the base.
I glass-beaded the base and used the correct 2-part Dicor.
The stripped screws were replaced with larger screws.
Look at my photos and remember that this trailer was stored indoors and was only wet five times before the photos were taken.
Antenna Fix & More