visible="false" includeInLayout="false"to the particular mx images (graphical Search Buttons) that you do not want shown. Make sure you don not try this for the eDrawBtn or the pBufferBtn to disable those just set them to false in the SearchWidget.xml
<enabledrawgraphicbutton>false</enabledrawgraphicbutton> <enablebuffergraphicbutton>false</enablebuffergraphicbutton>