Instead of searching like mad to try and find out what items were released when I decided to make a nice easy list to help. If you know which items are missing in which months, just tell me and I'll update the list.

2003:

Angelic Halo - Jun 03
Panda or Kodiac Grizzly Bear Hat - Jul 03
DJ Studio Headphones or Portable Stereo Headphones - Aug 03
Mini Angel or Mini Nitemare Wings - Sep 03
Angelic Sash or Devil Tail - Oct 03
AFK or OMG - Nov 03
Nitemare or Angelic Scarf - Dec 03

2004:

Emo Bag - Jan 04
ZONY Discman or ZONY MP3 Player - Feb 04
Fuzzy Penguin or Baby Seal Slippers - Mar 04
Bammi or Hammi Hat - Apr 04
Angelic Pendant or Horns of the Demon - Jun 04
Steel-Plated Ninja Band or Kitsune Mask - Jul 04
Golden Laurels or Winged Anklets - Aug 04
Bani or Goti Clips - Sep 04
Demonic Pitchfork or Staff of the Angels ? Oct 04
BTK Hat - Nov 04
OMFG Hat or Fire or Ice Gauntlet - Dec 04

2005:

Demonic Pendant or Angelic Bracelet - Jan 05
Lunar Cloak or Solar Cloak - Feb 05
RoRo Robo-Puppy or Kiki Kitty - Mar 05
Prism Butterfly Mantilla or Chestplate of Arachne - Apr 05
Guitar of Angellus or Demona - May 05
Bone Dragon Helm or PHoenix Circlet - Jun 05
Solar Headdress or Lunar Cowl - Jul 05
Whip of Fire or Ice - Aug 05
Hard Shell Pack or Pandy Pack - Sep 05
CoCo Kitty Plushie or Wind Security Blanket - Oct 05