Let me know how you make out on this.
I have a similar problem with one of my customers running an ancient database on Filemaker Pro Server 5.5 . Some time ago (probably last time the software was accessed, long before I started there), it appears someone may have dropped the CD on edge which has cracked the disk and it isn't read/recognized by any computer.
The computer the database is on is still working, but is on it's last legs and desperately needs to be replaced.
Hopefully we can both find an answer to the problem.
If anyone out there has a copy of this old software, please contact me, I'm willing to pay for a replacement CD, I just hope a solution can be found before the system physically dies.