assuming the mast foot of which you speak is the block which fits into the base of the mast and forms the top piece of the hinge, having broken the nipple through which the hinge pin fits, i was able to get a new one arc welded and ground to shape, $145, at a machine shop, they quoted over $500 to build a new one out of stainless steel, i tried for ayear to find a replacement without any luck so good luck to you
jim