Each frame of film was made as a cel, with light shining through specific areas... I've got an interesting idea on how to replicate this effect more faithfully.

This will involve what little I know of Blender. I haven't actually done this myself, so I don't know how practical it would be. While I know much of Blender's capabilities, its convoluted interface has always stymied me when it comes to creating anything impressive with it.

Here's the basic idea. Make a plane and point the camera directly at it, so that it takes up the entire field of vision. Use the actual video (or maybe just one frame of the video) as the texture. You've basically just created a movie screen.

Now comes the hard part. Begin removing all of the parts that light is supposed to shine through. Something tells me that an enormous amount of curves is necessary for this. I could be way off course on this for all I know. Perhaps you could just color in the areas of the frame ahead of time in Photoshop / Gimp and just tell Blender that specific color is transparent.

Now that you've got that taken care of, set up a colored light behind the video and shine it through.

Basically you've just created a virtual lightbox.

If anybody wants to try this out and tell me how it goes, I'd love to see the results.