The disks, are they scored on the surface, with concentric circles or just spotted with mould or dust on the surface?
Quite often if you slide back the metal disk cover from the front of the floppy you can see the surface, and if you use a pencil in the underneath outer drive cut-out you can turn the disk manually to see if there is any mould or damage to the floppy disk magnetic material or it's surface.
If it is mould then the disks can usually be cleaned with some multi-surface surfactants/cleaners, like you get in the supermarkets, but you will need to dismantle the floppy disks to be able to do this. Generally this method yields good results, and you can get a disk to work fully, if the mould has not eaten/destroyed the magnetic material itself.
You can usually tell if it mould on the disk, if you cannot see any concentric circles on the surface of the magnetic material, and the floppy disks squeals or makes a lot of noise as it tries to spin in the drive.
If it is mould I can explain how best to do it, but if it concentric circles on the disk, then I wish you the best of luck because you are not that likely to get the essential data off them in a complete enough format to be able to use the data as it was written.
If the data is for games and if they are not the originals then you can usually get the disks from off the WWW, if it is data from applications then some can be obtained via TOSEC, or if not available there I have some data backups of of Amiga software, though not inexhaustable, if you need any further advice then PM me.
Hope some of this information is of use to you.
