Adust
the shadows
(make your blacks blacker)
Version
5
Menu Colors> Adjust> Highlight/Midtone/Shadow
Increase the shadow slowly up from zero
until you like what you see.
Version
6
Menu> Layers> New Adjustment Layer> Levels
Type a higher number than zero in the Input level's first field
and further experiment with the controls.
Experiment
with
your Colors> Adjust> Brightness Contrast,
depending on your original photo and the desired effect.
Add
some noise for aging (not shown in examples)
Menu> Image> Add Noise
settings 10%-15% Uniform