Mellotronists

As far as I recall, M-400s started at serial # 100.
 
Here is an email I just received on my myspace site.
 
 
"Hey Frank,  

Nice to know there's another Mellotronhead in the Old Dominion. I own a  M400 
s/n 121, which has a pension for playing radio station broadcasts louder  
then it's own tapes. One day I hope to speak with you about a restore of the old  
girl. 

Jim -
 
Portsmouth, VA  "
 
So  this would be truly #21 then. That would be the oldest I am aware  of.