I'm trying to understand your problem. If you can see an edge of the video window, aren't you able to move the entire window ? OSX won't allow you to move the window up past the top of the desktop, but you can move it all the way left and right and downwards by grabbing the top or side edges of the window.
If you can play the video in Classic with QT 6, then you can also move the window up past the top edge of the desktop.
Other than that, if it's very important to you, I suggest borrowing a CRT monitor to view all of this video.
G4 533 DA, Mercury Extreme G4 1.33GHz CPU Mac OS X (10.4.8) ATI Radeon 9200, 1 GB RAM
G4 533 DA, Mercury Extreme G4 1.33GHz CPU Mac OS X (10.4.8) ATI Radeon 9200, 1 GB RAM