Afternoon Alan,
On 'My Flights' and with full ADSB (currently NW of Valencia) is 3435C2 an Airbus A330-202 MRTT registered EC-331. According to Airframes it was due to go the USAF but ntu and is due to go to the RSAF instead hence the flight ID of RSF3837. I don't know if that is significant with regard to it's possible Saudi reg. I have gone into Database Explorer and entered all the various details inluding the c/n number given on Airframes of '996' but for some reason although it is being accepted in the d/b it shows on screen as c/n 'Various'.
Over to you.
Ian