FCP Reports Incorrect Frame Rate

I am new to the forum ... so bear with me if this question has already been answered.

Foolishly I re-organised my film clips using finder. I now know that this is a mistake. I moved them on to an external drive.

I then tried to relink the files in each event. In most cases this worked. However some files will not relink. The file is found but then rejected. On looking closely, the info on the missing files as listed in FCP is wrong. The frame rate are seemingly random and the lengths slightly different. There is no doubt that the files are the originals but it seems that FCP has somehow stored the meta data incorrectly and now will not relink.

I have been looking for a common attribute of the failed files, and it might be that they were all filmed using 8mm - an iPhone app. I am not sure .... however if it was a bug in 8mm then surely I would not be able to import them in the first place but they all work fine in any application and are correctly identified if I re-import them to FCP.

Of course I could simply re-import, but then I lose the edits on about 40 videos, which (to say the least) would be tiresome.

The obvious question to which I cannot find an answer, is whether I can somehow change the meta data or force the relink?

Thanks
Mike