I haven't studied all the replies, but it would seem that it would be possible to add a flag for the name, and secondary name fields.
Step two would be to use the LOC (or other local public library) or non-Amazon site to pull the name, which is based on the users data entry, and place it in the new name file. If there is no information available then allow the user to manually enter the names of the writer and book name. The flag field can be used to automatically verify that the information comes from a non-Amazon source, or was manually entered.
As a final process, the new information can be written in the original fields, with a flag that it is safe to use in a sync.
Obviously only the new fields would be used for syncing.
When new books are added you would be able to (1) first use a non-Amazon source, (2) set the flag for "safe" data and (3) allow syncing.
Another option for some of us with Bento would be to add a template in the Template Exchange system that have. Donations only, but might work.
http://solutions.filemaker.com/database ... x_home.jsp