A B757's right engine amber thrust reverser REV light illuminated at cruise altitude in turbulence. An emergency was declared with a return to land. The REV light extinguished but on final approach the SPOILER light illuminated accompanied by a pitch up during the landing flare and after the nose was lowered to the runway.

Narrative

Two hours into flight; experiencing continuous light to moderate chop; encountered right engine thrust reverser amber REV indication initially flickering then illuminated steady accompanied by fluctuation in EGT. Declared Mayday with Center. Received clearance to make a right descending turn to FL250; engine out cruise altitude; and proceeded direct an enroute VOR. Reviewed aircraft QRH. Level FL250 smooth ride. Right engine amber REV indication went away. Engine operation and indication normal. Continued divert/return to our departure airport. Established on ILS DME Runway XX just past the initial approach fix; spoilers enunciated and illuminated advisory on EICAS. Review aircraft QRH. This problem caused an uncommanded pitch up during the landing flare and during landing roll after nose gear touch down. Placing nose gear back on runway used additional distance for landing roll. Exercised Captain's emergency authority; landed overweight; flaps 25; aircraft gross weight on touch down 209;400 LBS. Airport fire and rescue team met aircraft. Taxi in and parking uneventful.