Thanks for your post George. See my answers below:

Have the server admins looked at this? --> Yes, they looked at it; I don't know for how long, but they didn't come up with anything.

When you view through explorer are you setting the options so hidden and system files are shown? --> Yes, I had thought of this and set the options to show hidden and system files.

does the sizes shown for the log files in master.sys.master_files match to what you see on the file system? --> Yes, but I had to reboot last night and did not run that query until today when I saw your post. Right now there's lots of free space but as time goes on and space decreases I will run that query again.