While Trash capability is enabled on a default installation and custom post type when testing here, if the Trash option does not display, then it may be a sign that the content was deleted and the trash emptied.
Check with your host for backups that might contain the content, or if it was published publicly, check the Internet Archive.
If looking in the database directly, the content would be in wp_posts table with revisions in separate rows, and field values would be in wp_postmeta table, sorted by field key and post ID.
