You can search for Sellers via the Advanced link to the right of the eBay Search window. Scroll down to the Seller section and enter the ID and complete the Search at the top or bottom of the page.

Do you know the account username? If so, what happens when you try to sign in? If not, try signing in using the email address connected to that old account in place of the username. If eBay prompts you to create a new account when using the same email address, that is an indication that the old account is likely gone.

Your username or user ID is the unique name you chose when you created your eBay account. It's the name other eBay members see when you're buying or selling with them. You can change your username in the personal information - opens in new window or tab section of My eBay or by selecting the button below.