Return multiple data elements

Using Xquery, how can I search the file below (consisting of many items), for all items with 'XC' in the part-number (there are many), then for matches return all 3 of the interesting data elements (part-number, part-name, and name)? The return is the main problem--my attempts result in every permutation of the interesting data elements. Thank you!

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<catalog>
   <item>
     <description>
    <partref>
       <part-id>
        <part-number>XC51222</part-number>
       </part-id>
    </partref>
    <part-name>DSP, Network Vectoring<part-name>
    <vendors>
       <vendor1>
        <pay-to>
           <name>JCOF Industries</name>
        </pay-to>
       </vendor1>
    </vendors>
      </description>
   </item>
   <item>
   </item>
[many items…]
</catalog>

xquery version "1.0";

let $sep := ','
for $x in catalog/item
where fn:matches($x/description/partref/part-id/part-number, 'XC')
return fn:string-join( ($x/description/partref/part-id/part-number/text(), $x/description/part-name/text(), $x/description/vendors/vendor1/pay-to/name/text()), $sep)