Allright so i saw a couple of posts about the S4 gear ain't in the WDB editor in Glitchy's MES (Of Awesomeness) so i figures out this lil way to add the missing models.
1) First off go download the latest version of WoW Model Viewer (WoW Model Viewer)
2) Extract WoW Model Viewer to your desk and open Items.csv
3) Search for the model you wan't use (I will use Muramasa in this guide)
It should look like this: 34214,48079,2,7,13,32,4,Muramasa
4) Open you Glitchy's MES folder goto data > WDB > items.txt
5) Go to the bottom of the text document and write in the name "Muramasa"
6) Now go back to the Items.cvs file and find the Model ID (It's the number after the first "," so in this example it would be "34214,[48079],2,7,13,32,4,Muramasa")
7) Go into "items.txt" again, to where you wrote in "Muramasa" and add a "," and then the Model ID "48079" so it should look like this: "Muramasa,48079".
Save, close and start up Glitchy's MES and now you can model your weapons into a Muramasa!
Hope this helped!