While looking this very interesting video(http://vimeo.com/26251829) where you see some steps in lens manufacturing at Leica and taking the numerous manual interventions in consideration, lenses cannot be all the same.
Text underneath the movie screen:
I wonder how Nikon lenses are made, with the same, more or less manual intervertions.Every Leica lens is hand-crafted and goes through meticulous manufacturing processes to uphold the quality and precision that Leica defines and customers have come to expect. In the age where technology almost inevitably means mass manufacturing, Leica products are still made with exacting precision by the hands of highly-trained technicians.
This video gives you a behind-the-scenes look at the craftsmanship and making of Leica lenses in the production facilities of Leica Camera AG.
Your input and thoughts on this topic are welcome.