Missing photos

So, I think I have created a bit of a muddle with my photos... I have moved from Mac to Windows and from keeping photos on an external HDD to a RAID home cloud set up.  Because of this I have broken all the links from my LRC folders to the original photos.  I think the remedy to this is to copy all photos back onto an external HDD (too many for the PC to handle) and then, in each folder to select a photo and go through the find photo option (selecting find nearby photos at the same time) to re-establish the link.  This will be a bit laborious but I do not know of any other way that might work.  Any suggestions or tips would by very welcome if only to confirm that I will have a few hours work ahead to achieve this.  Thanks.