It is fender mounted. I believe that it was originally a power antenna, but whatever. It is broken off at the "hub" or where it goes into the fender. I dont know if that is what you are referring to as a mast or not. The handle on mine no longer opens the door, so I figure it is the plastic mounting underneath the panel that is broken, so when you pull the handle it moves instead of pulling the release arm. At least that is what I think has happened, I havent checked, but it has occurred on two other handles so far. Let me know, and thanks for the quick reply!