I don't know if this helps at all, but here are a few pictures from the innards of my 4g, non color.  So I don't even know if this will be the same as the color, but it might be.  The connector to the click wheel is in the bottom right if you were looking at the iPod from the front, is about 5/32s of an inch, maybe more like 11/64ths and has 8 connections.  I don't know what pin does what ... but if the connection on your 3g is the same dimensions, maybe they didn't change anything.  If you decide to go through with it, good luck.
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15" MBP late 2008