First it might be helpful to know the OS revision of the 3000, is it 3.1? Or still the old 2.x? Also how big's the drive? I'm thinking your best bet would be to plug the drive back in, then turn the machine on with the boot disk in the floppy drive. Access the early boot menu by holding down both mouse buttons when the machine is turned on, and select the boot floppy as the bootup volume.
Once the machine boots with the floppy, you can tell which partitions of the hard drive show up on your workbench screen, and go from there.
You might want to get a copy of disksalv and run it on the disk, it will likely be able to get the problem partitions fixed/mounted enough for you to get your data off and onto another disk. Good luck!
