Hello Herbert, Alan and Bill,
the Santorin main mast was not fitted with the welded aluminum like on the SM2K.
Here are pictures of an SM (before SM2K) masthead with a stainless steel support bolted onto the aluminum flat part at the top. It is, of course, isolated with a plastic sheet to prevent galvanic corrosion.
This plate must be strong and the welded eye that supports the block's shackle must be reinforced.