Questions Fixed Assets - Errors in Imports - Errors in posting - Can client return to blank FA DB?

We have a client that has been through their implementation of Fixed Assets and noted that after about a week of work determined that there was an error in either the import or initial processing that has duplicated records in the posting books.  The goal at this point is to determine if there is a way to reset FA to zero.    The client has a very specific FA numbering system and they do not want to change them.  There is also no CHANGE ID function in FA that could be used to update the bad and reimport the good.  It would seem odd that no one has ever encountered this and we are hoping that perhaps someone can suggest a method where FA can be reset, either as if it hadn't been populated with records, or how the current records can be dropped and new records, with the same numbering be entered.

I realize we're making it harder by limiting a few of the things that could be done but we always try first to give them what they want.  

Any ideas, assistance, guidance, would be greatly appreciated.  Feel free to let me know if you need any additional data detail and I will provide.

Thanks!!