For light staining I use 1 table spoon or less soluble coffee in a glass of cold water, throw it in a shallow oven tray or something, let the paper soak for a couple minutes max then place it in the oven (not too hot) until dry (usually a couple minutes too). It gives a nice yellowy/old paper homogenous tone. You can drop some more concentrated coffee in some spots to make stains or let the paper absorb it through the edges too to add some texture. Results will depend on the paper's weight, thickness, grain etc so it's better to make some tests and tweak soaking time or coffee concentration. Different kinds of tea make different stain hues too, but I haven't tried it that much cause you've got to make the tea... with soluble coffee you can make a ton of old looking paper in a short time. I also prefer to print in plain B&W or color on white paper and give the stain through this method, instead of printing the stain. (Sometimes ink runs or reacts weird especially on my home el cheapo printer)
Is this from the actual 1984's "1984" movie? Very cool project btw!