The trouble, money and time that went into bringing
the barony out of abeyance would make a
very interesting subject for a book.
I don't have Debrett's to hand but I think a previous edition
published a special article on the Grey of Codnor case, authored by
one of the heralds. I think it was the 2000 edition, but not
absolutely sure.
I see Debrett's make reference to the numbering of the title holders,
referring to CP vol VIII, where the earlier holders are included in
the enumeration.