I know this is probably frown upon. My good friend has a professional modding service for headphones. He has the ability to make single sided headphones dual sided and vice versa. Has the ability to make 3.5mm headphones into 1/4 inch. Also have the ability to make open headphones closed and vice versa. The moral of the story is if you can dream it up he can do it for you. If anyone finds this link not applicable to headphones then by all means flag it. I know once you look at his work you'll be impressed and probably want your headphones modded. This is a link to his completed work.
Here are some pictures of one of his more complex mods. Painted, new mesh, detachable custom cable, new custom driver etc.
Stock Takstar 2050 headphones
Since I am new I can only post 2 images. I would post all the inner mods but I can't