I have a somewhat different advice/experience.
AF will accept electronic receipts.
But don't hesitate to include receipts for over the Montreal limit.
AF is likely to adjust a usage discount to old items.
As long as you have receipts for the majority of items, they will take into account some small items where you do not have receipts.
This is a judgemental thing, so it might depend on your status, the class you travelled, suspected exaggeration, etc...

As an anecdote, I once lost a golf bag from SFO to CDG (travelling F).
Luckily a friend know the SFO station manager who embarked in a personal search. It happened that US customs had selected the bag for inspection and left it in some holding place that no one ever checked.