.7z files are originally made by 7-zip, which is my new favorite compressing software, since it's free and has a higher compression than WinRAR's .rar files.
As for your model being glitched, i still don't understand what causes it, as i had the same issue with people with the V1 and V2 aswell. The model is from the 3.2.2 client, so there shouldn't be any issues, and those who have 'em are kinda on their own...
Need you to answer a few questions so i can dig through possible causes.
1) Are you using WoWME or playing the game without? (afaik, you don't need it anymore)
2) What client of WoW do you have? Burning Crusade or Wrath of the Lich King?
3) Also, 3.2.2 alright, but what language version? (check Data folder, there's a subfolder with the name i need, in my case it's called "enUS")
4) have you any other custom MPQs in your WoW's data folder?
Here's the files that belong there by default:
- common.MPQ
- common-2.MPQ
- expansion.MPQ
- lichking.MPQ
- patch.MPQ,
- patch-2.MPQ
All other files in that order are custom, and a) shouldn't be there when patching your game (as it causes errors later on), b) could interfere with this edit, although shouldn't.