I took an old Philippe "MajorTaylor" stem to the plater's recently to remove the old pealing chrome prior to polish & replate.
Under the chrome I was surprised to find that it was made from two rather than three pieces: I expected three pieces: quill, lug and extension with some fillet brazing.
Instead there was only a quill with a "built-in" lug and an extension.
See photo at: http://www.flickr.com/
It looks as if the built-in lug was bulge-formed. But bulge forming dies are expensive ... used only when the quantities justify the expense.
Could there be another explanation?
Amir Avitzur
R"G, Israel