== Bells' book == 

 I just got Bell's book, IMO he was about as good as Feynman in explaining matters. If you don't have it I can send you a scan of the intro to his spaceship discussion in his chapter "How to teach special relativity".  

 BTW I fully agree with Bell when he wrote that those who know something of the reasoning of Larmor, Lorentz, Poincare and Einstein, have stronger and sounder instincts (he propably meant sounder instincts than mathematicians).  
 Regards,