tomy Stepney differences I found

Thanks for that overview, Muddy. 
As we can see, Stepney is another character that needs to be re-released (with improvements, of course) in the future (or in another universe).
I mean, Stepney is an original character (from the pen of the Rev. Awdry), and all three versions are... well, not that good: too many stickers (why on earth is that number a sticker?), and they stand out conspicuously and shout: I am a sticker!... Really sloppy.   
Stepney is a nice engine; he deserves better!