As far as I know, after reading related topics on
http://forums.gearboxsoftware.com/, the ULCE is
53,160 overall copies.
So, there should only be 17,720 copies per platform (PC / Xbox / PS3), if it's equally dispatched.
Certificates are common for all 3 versions 'cause it "counts" the number of manufactured Chests, no matter what the version of the game is in for (PC, Xbox or PS3).
Concerning the missing Marcus Bobblehead figures, there's still no official answer from Gearbox... But most of the people complaining about the missing item had pre-ordered or bought their ULCE at Gamestop. So, rumors start to spread about a Gamestop's trickery.
Anyway, there are just rumors... And a problem on the assembly line is possible.