An option could be the sticker on the front face of the key, like this
Show Image
(http://www.diatec.co.jp/image_prod/FKBN87MEFB2_01.jpg)
It really depends on the sticker material, i tried the dual language one on my thinkpad anth the feel very good, tried out of curiosity the fluorescent ones and the feel, well...
like stickers (glossy, relatively thick, and plasticy)
Take also a look here, could be the easiest way
http://geekhack.org/showthread.php?17272-Buying-keyboard-on-taobao.com&highlight=taobao
I found also a couple of images to see how those keycaps looks on a backlit keyboard.
Show Image
(http://kbc.5d6d.com/userdirs/c/4/kbc/attachments/day_110423/1104231202f9cee215b1a0af75.jpg)
Show Image
(http://kbc.5d6d.com/userdirs/c/4/kbc/attachments/day_110423/1104231202b090a69630ab8342.jpg)
Not really nice to see after backlit and it give me a feeling like the LED/keycaps is bleeding(severe one)... May be it is time to peel off more of your original keycaps to achieve a same results?
Off-topic: Is that an modded BWE instead of BWU?(the braided wire seems like BWE version and there is LED under spacebar). AFAIK, BW having different sized Window Key too, so that mean he modded it too?