An interesting take is to scan a film frame and use this noise frame as an overlay. In the following photo, I have moved the grain layer halfway to the right so that you can see the effect more clearly:

![scanned film grain example][1]

This is how the grain looks in a detail:

![close look at the grain][2]

I’m not sure what the compression will look like in the resulting images, I’ll probably upload a better version somewhere else in a second.

  [1]: https://i.sstatic.net/wOmUq.jpg
  [2]: https://i.sstatic.net/Jzq3v.jpg