G-OSRA

It appears that this was the final 727-200 built by Boeing which was delivered in 1984 to Fed-EX.
 
It was sold to 2Excel Aviation in June 2013 as part of a fleet of freight aircraft.  They are now in the process of modifying this plane, and its sister (G-OSRB), to be used to spray dispersants onto oil slicks in the sea.