There are different styles but for this style application for example the Catalina 22 swing keel has what we call a brake style winch when you stop moving the handle it will brake or not move. I am not sure of the make of that winch but I find it surprising that if the handle is in, it will not release. It could be no one wants to touch it for example hitting a knee against the handle and that is a ouch!
I always told my customers whether new or used paticuraly the older boats like in your case, to leave that swing keel down. Why? Should it be all the way up and the winch or cable fails, it will come down hard and most likely damage the hull and some boats have sunk as a result. My suggestion is to leave it down always when in the water and only winch it up after running aground, coming into a slip where a cable or bracing is underneath or simply putting on the trailer. In the case of the trailer, you need to rest that swing keel on the keel tray to keep it from bouncing up and down so no damage will occur.
There are two things noted above. First, I do not know what the holes on the left and right for. Is it for sticking something in to lock that winch, screw hole or on the right could it be for an additional rod to turn that with if you do not have the winch handle.
In addition below you will see a W which is the logo for Wichard. I looked at the catalogue on file but none appears. There office is in Charlotte, NC but the area code does not match as I think it is in MD but you can try it. 401-683-5055.
As for the winch brakes seen on the Catalina 25 or 22, not sure who it is made by but you could call Catalina Direct or simply call the Catalina parts store which is 727-544-6681 ext. 266 to see who makes those and then look it up. Let me know what you come up with.