Very unusual combo, but looks like a great survivor!
I looked up the specs in my '74 Salesman Album and you can see them below.
If the car is all original as it appears this is my best guess --
64 paint code (Silver), WW Vinyl Roof (Silver Taupe - Only available with code 64 paint), B carpet code (it looks to be black) and XT interior trim code (Type LT specific)
-Luke