Looking at the cost of a mast I am not sure I would sail this and only motor in wind less then 10 knots and flat sea and get fix as soon as possible. I know there a lot of knowledge on this board but this is a big decision and one you do not want to be on the wrong side of. I would maybe find another tube and sister the brace using hose clamps to hold it in place. I am being ultra conservative, do to the cost of a new mast.