I wonder if it would've been better to use contact heads (connected to something like a Kryoflux) and spin the disk much slower, thus preventing more damage from occurring in the process. One of the first things taught in data recovery is that you should never put media which is known to be physically damaged into a drive and attempt to read it that way...
the heads were more durable, to be sure, but the SCREECHING a disc would make when one crashed... it was loud. I used to have a spare 14" platter that showed the gouges. Car brakes don't get scored that bad.