Thanks @Turelus!Might be something the people over at UESP could help with as they have a lot of image files, might be someone has a psd version.
Not actually sure of any of their forums names other than @Enodoc though.
ESO's source files are all DDS; I don't have Photoshop so I can't turn it into a PSD unfortunately, but I can get you the DDS.
Are you just trying to separate the logo from the background? If so, the white background ones should be easy to do that with. You may need to anti-alias the edge after cutting the background, but PS has tools for that.