In such situations, I have had very good luck reformating the drive on a PC with an Adaptec SCSI card. If you have such available or have a friend with one, you may be able to recover the drive.
The older Adaptec cards such as the 2940UW have an option at start-up to press ctrl-A and enter the firmware routines. One of those routines will do a low level format of the hard drive and I've found that that will usually recover the drive for Macintosh use.
Since you can probably find a 2940UW for $10 or lieing around in a ditch waiting to be picked up, your biggest obstacle would be coming up with a PC to try it in.