Watch out for the binnacle bolts. I removed my binnacle today for clean-up and three of the four bolts broke off! I wasn't using much force either. Two broke off right away. On the third, I was able to spin the nut off, but the bolt broke when I tapped it upward with the hammer; it broke right off.
Turns out that they are aluminum machine screws and they corroded where they passed through the steel backing plate/mount for the sheaves. Of course, there was water leaking, causing the corrosion (leak is one reason for my removal of the binnacle).
I don't know if mine is an anomaly, but if your backing plate/sheave mount has rust on it and one or more of the four nuts on the underside is rusty, you probably have corroded fasteners not holding your binnacle down.
I guess I have plenty of time to continue thinking about ground tackle while I take care this steering issue. :)