Not sure if anyone here has run into this but I was in dyer need of some specific case screws for my Antec 1200 build. Going to some of the local hardware stores, they don't carry the standard 6x32 or the M3 type screws in stock so I connected with a guy on EBay who sells these size screws and more. He also had the very specific Antec 1200 and 900 HDD screws with the unthreaded sleeve.
If you're having trouble finding any of these screws (not just the Antec series) you might want to hit him up as I believe he has quite a stockpile available.
His e-mail address is: [email protected]
The guys name is Larry and he was extremely helpful and friendly so I have no problem recommending him here.