Some days later, I was roaming around town, knowing that the computer would be available for me to take home in a matter of minutes, and received a call from the store. Apple had sent in the wrong spare part: instead of the light grey keyboard casing for my white MB, they sent a black one. I was told that it would unfortunately take an additional day for the correct part to arrive.
I objected, not in a serious tone but half in jest, that they should bolt on the black casing and let me have the computer right away. Being answered with a rather amused "why not", I said I'd traipse into the store to see how it would look. It looked good. Some clerks gathered around to positively comment on the rather unorthodox looking Mac, and without further thought I asked them to pack it up to go. Result (the pictures are low quality and don't really do justice to the proper item):
Later, I googled the Internet Machine Space for similar configurations, and found out that what I have is actually called a "Panda" MacBook by some. Superficial MacBook modding seems to be rather popular amongst enthusiasts, but my mod is special – it's the result of serendipity.