On 10th, I rode on 9104F set of Seibu 9000 Series, whose door pocket windows patched by yellow-coloured steel plate from their behind and advertisement space newly made at the remain of them.
The side view of 9104F around a door. Against refurbished 2000 Series whose door pocket windows were completely removed, that of 9000 Series keeps its original.
The silver line from the bottom of the ad space tells there used to be a window. Above the space is the same way covering the window as refurbished 2000 Series.