Copy paste and transform the pieces and make a shape to build the chariot
step 3 of 5
Copy the stone texture to make the floor and the background
step 4 of 5
Transform to fit the floor perpective and make the background, copy the texture to ca new layer resize it a lot to give a rough effect.
step 5 of 5
On new layers, use multiply and overlay modes, to paint the shadows and highlighs.
Change the brightness/contrast and lower a bit the saturation to finish