Thanks!
Here's a pic of the piece. Thank you all so much for your replies! Yes, it is that little part on the end cap. The boat is a 1979 Ericson 25+ that I bought last summer that needs a lot of work before sailing that I am just getting to (I had it covered over in the harbor all winter). I wasn't planning on a new boom among the many projects that need to get done, so I'm glad there may be a relatively easy fix! Most of our marine services here are geared to fishing boats, not sailboats, and it can be hard to find services for sailboat matters, but I'm sure I can find a welder.
I appreciate the detailed instructions about drilling out the rivets. I also appreciate knowing that I can sail with it that way.
I keep telling people my learning curve is straight up on all of this, but it's really climbing up and around the power curve to get on top of things--on every little thing (though I'm loving just about every minute of it, despite the setbacks). I very much appreciate all of you taking the time to help.
I had the boat out of the water recently to check the bottom (luckily it had a prop in good shape) and paint and zinc. Here's a pic while it was in the yard, with one of our Juneau rainbows (this is rainy rainforest country).
Cheers,
Patti (aka Alaska sailor)
the Alula (Latin for "winglet")