Assassin's Creed Unity Incomplete Memento Collection Issue

I am a completionist and have recently completed everything within Assassin's Creed Unity except for the memento collection. It has 3 mementos missing. They're now impossible to collect due to the discontinuation of Club Competition. Therefore, I am looking for a workaround regarding the matter. Perhaps if there is an active Club with 11 out of 11 objectives completed and I can be a member of it, my memento gallery will be complete.