The way Collections work on AO3 is You have to add them to the Collection, it's not something I can do. It's just like adding any other tag to the work. If you go to edit any piece, on the main page (in case of multi-chapter stories), one of the many listed items on the left as you scroll down is: Collection, or Add to Collection. If you follow linvro21's instructions All the fic/art/entries on your account will show up at once with a checkbox beside it and you an go through and check off all or some of the work that fits into each Collection category. It's pretty easy, it's more a matter of noticing the Collection line item in the list of stuff and knowing what to do with it. For example Sam and Dean the OTP LJ site already has a collection set up.

I'd add it at my end IF I could, but that's not how AO3 works.

Then you can bookmark the Collection you want and I think you will get advisories each time something is added ( not sure on that) AO3 may just remember your favourite bookmarks.

Good luck! And so nice of you to save these orphan, but oh so wanted stories.