Spreader base plates
John, the PO of my boat had one of them welded up after it cracked, and so far it has held up well. It is cast alloy, and I don't know exactly what the composition is, but obviously it can be welded. My boat is a '76 E-23, but the spreaders are pretty massive and foil sectioned, not round. I suspect your base plates are the same as mine. Make sure you have right amount of up-angle on the flange so that the spreaders come pretty close to bisecting the angle of the upper shroud.