Send the seller the transaction number from Paypal.
That's all he needs.
Tell him the PP name you paid to. Sometimes members will change their PP ID . Since it is an email address, closing that email account is a possible reason for not getting paid.
Sometimes a buyer will misspell a PP ID.
If he can't work it out from there, especially if he wants you to 'repay' to a different account, go here;
http://resolutioncenter.ebay.ca/
and open an Item Not Received Dispute.
The seller then must either refund you or prove that you have received the item. If he does neither, PP will refund you and go after him for their money.