Mellotronists

WOW!!! this a rare one. 

On eBay is the only M4005 I have ever seen. Oddly, the serial number is 804. 
Yet I have never seen another. Call me confused. The photo of the inside shows 
a special looking "computer like" control card. Could this be the secret? 
Should we all look forward to the new M4006 in the near future? Or perhaps Dr. 
Korb will bring forth the next gen JK Mk 4007. I'm quivering with anticipation.

Duncan D. Nutz