Well the restore & reload of the iPod should take care of the removal of the albums from the ipod.
(Later)
Well the restore didn't work. 😟
However, whilst it was restoring, I inspected the file "iTunes Music Library.xml" with a File Viewer and did a search for Jean Michel. Interestingly, I found that 2 tracks were tagged in the "Sort Artist" tag-field, with a variant of the Artist name; and this field was blank in all the other tracks.
I hadn't previously known about this field; but once I deleted the two entries from "Sort Artist" and re-sync'd the iPod; the two Jean Michel entries merged to become one! Eureka 🙂
Thanks,
NigelS