FCP: How to recover one project from yesterday's backup without losing today's work in the same library?

You are a GOD! Yes, I had FCP backups in my Movies folder. Yes, I had one from the previous night which was complete.

The old "Project 1" was completely ruined, so there was no need to worry about replacing it from the copy in backup. I opened the backup library and the new library, and dragged the project over from the one to the other. Since I renamed the old project "BAD" first, I was able to put it in the original Event where it belongs.

When I went to drag the project from one library to the other, I was presented with a complex dialog asking if I wanted copy include various kinds of media, or just the project. My original library was some 150GB, and the backup library was only about 5MB, amazingly. I'm guessing there was not a single piece of media in the backup library; just pointers to media, and data about project edits points, transitions, etc. And yet, that project in the backup library was playing back just fine. So my guess is that it still pointed to all the same media in the main library. In light of that observation, I selected the option to copy JUST the project and no media. That was not only super fast, but appears to have worked as expected: everything plays, and no clips appear missing.

This was a huge help. Other takeaways for me are:

1) be careful when you think you're editing a multicam or synchronized clip that you're not actually in one of your project timelines!

2) take project Snapshots to let you rollback in case you ruin a project

Thanks again!!!