Media managing

Hi,

I'm editing a short film and have in the course of my work saved the project as a new project file several times at different stages. Each project still corresponds to the same captured media.
I'm now moving to the online stage which involves re-transcoding the media from Pro res 422 to 4444. For which I need to make more space on my drive.

I have deleted some old sequences and want to get rid of the old project files and their corresponding files but without damaging the final project file.

I guess I should use media manager to do this, or should I use find?
I had considered copying all the final project and corresponding media and then deleting all the old stuff but I don't really have enough space anywhere to do this.

Whats the best and safest way to get rid of redundant media and render files from these old projects?

Thank you in advance.

Bailey.

(FCP 7.0)