Although "eBay (v1)" does not show the back side of the photo, "eBay (v2)" shows both sides and proves that the photo was published without a copyright notice.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.
Uploaded a work by NBC Television Audience Promotion (indicated by the back side of "eBay (v2)") from Image source: [https://web.archive.org/web/20210714202516/https://www.ebay.com/itm/313396594799 eBay (v1)] [https://web.archive.org/web/20210714202731/https://www.ebay.com/itm/164033522421 eBay (v2)]: [ front], [ back] with UploadWizard