A few months ago, I was given a hideously beat-up C128. Upon closer inspection, it had a printed serial number sticker instead of the regular sticker on the bottom, and another sticker that said that the machine was not yet FCC approved. The motherboard looks almost like a production motherboard but has slight differences. The serial number is 251.
Thanks to Robert Bernardo, I got official confirmation from Dave Haynie at this year's CommVex that this machine was in fact a developer prototype, presumably sent out to software houses in advance of the C128's launch so that there would be software ready for it when it arrived on store shelves. He even signed the case! That was nice of him.
Anyway, the machine wouldn't boot with the original motherboard installed, so instead of trying to fix it myself, I opted to replace it entirely. The machine is all cleaned up now and running perfectly.
I'll try and get some pictures later, but I'm wondering- is this machine worth much more than a production Commodore 128? I mean, it's probably worth less than it would have been had the original motherboard worked, but I figure this way it's still useable, if nothing else.