You can enter the ebay seller's id and item no. which you have transacted to get his details.
Here is the link
http://search.ebay.in/ws/search/AdvSearch?sofocus=bs&sacat=-1&catref=C5&sspagename=h:h:advsearch:IN&from=R7&nojspr=y&fsop=1&fsoo=1&fcl=3&frpp=25&sofindtype=9&pfid=