I searched too, but I cannot find any interior pix of Flagler’s #90 private car. It is owned by the Indiana Transportation Museum, of all strange places. So far I have not been able to connect to the museum website at www.itm.org. The photographer that took that exterior shot, Casey Thomason, works as the Corp. rail photographer for Norfolk Southern also. I’m hoping he took the interior tour and will post photos later. That is a real historical gem!
Edit: AHA! Video of the car ‘in action’ with a few interior shots of the Opulence!