Can anyone tell me the size (as in pixels) and MIME types for the following file types?

.ngg (Nokia Group Graphic)
.nsl (Nokia Startup Logo)

I take it that they are both renamed GIF files(?).

I have looked in "Nokia WAP Phone MIME Types v1.1" posted here in the Forum, but it is not complete.

Thanks (The MIME types are the main thing I am after)