I had to rebuild my computer and had moved my Aperture Library over to a portable HD.  But when I put it back on the new build and opened Aperture, I was horrified to realize that somehow a number of videos and original source files were gone.  Now I have little yellow triangles on a lot of pictures.  Generally I am not too upset as the pics I still have are the result of edits, which I desire to have anyways.  Is there a way to make the current version be seen as the original version and not have it look for a referenced file that no longer exists?