Back in May, a gentleman by  the name of Jeff answered this question for me, providing me the following instruction...and of course it worked perfectly.

Modify the aircraft config with this...fltsim.XX being your next availible number...
[fltsim.XX]
title=Captain Sim 757-200 1
sim=cs757-200
model=RR
panel=
sound=RR
texture=aa
kb_checklists=
kb_reference=
atc_id=N757
atc_airline=AA
atc_flight_number=757
atc_heavy=0
atc_parking_types=
ui_manufacturer=Captain Sim
ui_type=Boeing 757-200 RR
ui_variation=American Airlines
description='757-200 Captain' v.1.1\n(c) 2006 Captain Sim \nwww.captainsim.com
And then copy from "texture.nz" folder the textures...
57_RER_T.bmp
57_REL_T.bmp
Into "texture.aa" folder
Of course back everything up!...Like the .cfg...
All this does is direct it too the Rolls Royce model and change the engine textures.