Extemporaneous

I was looking at your spreader and I don't think it is the end of the world. If it was me I would get it welded and get dye penetrant to check for cracks. You can get it from any reputable industrial supplier. The kit comes with two spray bombs. One is a colored dye penetrant and a powdered developer. The instructions are self explanatory. Since the spreaders are mainly in compression I wouldn't be too concerned about catastophic failure. I hope this is of some help to you.

You have a great cruising boat. We sailed up the Red Sea with a Corbin 39 named Balmacara. It was a good sailing yacht, went well to windward, and they sailed it about 90% of the way around the world.