combining field data and allowing modification
I'm trying to combine two or more names of authors into an "author credit" field, for example, if John Doe and Jane Doe write a book together, I'd like the new field to suggest: "John Doe and Jane Doe". I would, however, like to be able to manually edit this without affecting the original records, in case they would like to be called "John and Jane Doe" or "The Doe Duo" or something.
The author name is a calculation (combining first and last name), and is a field in a table "person" that has another instance "person_author" which is related to a linking table "author_book" which is related to "book". The linking table contains author ids and book ids, to provide for many-to-many relationships between authors and books.
I've experimented a fair amount, with calculations, lookup, etc., but either see nothing copied into the new field "author credit", which I've created in the "book" table.
Any advice about how to proceed?