Hi.  We have two similar projects that we are looking at involving replacing an edge that broke off of an old terrazzo step/treadle.  In one case they kept the pieces that broke and in the other they did not keep them.  The step with the retained pieces is fairly straight forward I think because it just needs epoxying the chips back into place and filling in the spaces.  The other one is a little more tricky.  I have never tried to fashion a step bullnose with epoxy or other material and was wondering if anyone has experience with this.  Thanks so much for your comments.