No I had my plex library open and was viewing it then in a seperate window I simply copied in new versions of the videos (ones where I had simply added a -2 to the file name) which were missing and in seconds I could see Plex scan these changes adding 1 to it total of items and the video popped up in the library view! I did this for the remaining 8 videos and walla all were present 
I haven’t yet tried to remove the original named videos Plex had wrongly grouped together, I might just leave them well alone as they say let sleeping dogs lie as its not doing any harm leaving them in the video folder at least I can now access all my missing videos, well I can for that particular artist, as I expect there be many more within the 6000 odd music videos and I’m not checking them all it would take days! lol I still can’t work out why Plex had wrongly groups these few videos into one entry? I’ll guess I’ll never know? But yes an interesting idea this Plex dance I’ve done something simular myself when music albums have cocked up between albums with multible cds in one album and its normally caused by bad meta data settings between cd album sets of many cd discs, normally that can be fixed by using the merge tool in Plex, or doing this Plex dance with the tracks.
