[xsl] Assigning new attribute value

["Mark Wilson pubs@xxxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

I am doing an identity transformation that has presented me with a 
problem. The element <Location> in the original XML must have one and 
only one of seven possible attributes. Whichever attribute is present, I 
must keep its name but change its value. I have created a brute-force 
template that I assume will work. It ascertains the attribute's name and 
assigns it a new value. This is so ugly I am hanging my head in shame. 
There must be a more elegant method
Mark

xsl:template match="Location">
     <xsl:param name="placement-index"/>
         <Location>
           <xsl:choose>
               <xsl:when test="@minisheet">
                   <xsl:attribute name="minisheet" 
select="$placement-index"/>
               </xsl:when>
               <xsl:when test="@souvenir-sheet">
                   <xsl:attribute name="souvenir-sheet" 
select="$placement-index"/>
               </xsl:when>
               <xsl:when test="@gutter">
                   <xsl:attribute name="gutter" select="$placement-index"/>
               </xsl:when>
           </xsl:choose>

<!-- There are more attribute names, but you get the idea -->

         </Location>
  </xsl:template>