Boom, keel bolt, winch photos

Here are a few of the parts:
The boom has an interesting keyholed shaped hole where a boom vang MAY have attached. Don't know. The winch is the braking kind-thank goodness. Which means when you stop turning, it stops turning. Doesn't keep flying around with the weight of the keel. And the end of the boom has a squared hole which supposedly pops out so that you can reef by rolling the mainsail around it. So far: no popping out. I've tried WD40 and penetrating oil, but no dice. One of the many projects.