Displaying PDF attached to post on WP attachment page

We have an ACF repeater field ([login to view URL]) attached to WP regular post type (posts). Repeater rows have one file upload custom field where our editor upload 1-3 .pdf file(s). We need to display the link to this file(s) with file title as anchor text on [login to view URL] pointing to WP attachment page ([login to view URL]) where .pdf should be rendered through this PDF viewer plugin: [login to view URL] or, alternatively, google viewer. If google viewer is used we need a fallback in case Google Viewer service goes down. To illustrate better the scheme, we need to achieve what is explained here: [login to view URL], using pdf reader pointed above instead Google Viewer. Attachment template page ([login to view URL] / [login to view URL]) should match a specific theme and also preserve this theme sidebar functionality.