Re: What is This Piece of Metal on my Boom
That looks like a Catalina 25 boom. If it is then that is where the mainsheet used to be attached. Maybe your boat had an aftermarket traveler added to the front of the cockpit and switched to mid-boom sheeting?
The topping lift is mounted to it's normal place for a Catalina 25. There should be too holes, the forward one is for the outhaul and the rear one is for the topping lift.
On Catalina-Capri-25s.org you can find original manuals for these boats that show you what every single little part on the boat is.
boats that I sail on regularly: Pearson 28-2, Rondar 505, Yankee 30, Blanchard Junior