The e906, below, is the third generation re-issue.  The original reissue of the 409 was called the e609, the e609 silver has a mid presence boost and now the e906 which has EQ switches. 

While the original reissue is most desiable because it's actualy flat (and ribbon-like), I'd be willing to bet the mid boost on the silver version could be undone.  I've seen the e609 silver on ebay for under $100.

Not that I want to create a crazed market for this mic; I personally believe one reason it has failed in the market place is that Sennheiser charged too much for the first and third versions.  It really is a $100 mic.

Side view showing beautiful contrast 
of gold and black.