It is difficult to see but the part of the aluminium through which the bolt passes has disappeared. It isn't a problem at the moment but we are thinking of dropping the mast to replace the rigging and are afraid that the step might disintigrate.
It shouldn't be difficult to have one made.I'd favour stainless even if some sort of insulating arrangement would have to be made.It's much easier to find a stainless steel fabricator than an aluminium one.You should drop the mast as a matter of course.If the mast step is desintegrating it must be renewed.