You can't read them meaning you no longer have the drive or the disk cannot be read ?
Last time I checked my disk was back in 2012 and they are all OK except one making a snapping sound.
Those disk are durable as they are made to withstand removal and transporting.
Each disk has it's own head and if sealing/vacuum during run time is still intact it should be able to read/write them.
So if you cannot read it due to this, putting on another drive will also not work.
Unfortunately, I have packed them all into the cupboard including my Falc as I am mostly on my FB nowadays.
My Stuff: FB/Falco
n CT63+CTPCI ATI R7500 14+512MB 30GB HDD CF HxC_SD EtherNEC/ TT030
68882 4+32MB 520MB Nova/ 520STFM
4MB Tos206 SCSI
Shared SCSI Bus:ScsiLink ethernet
, 9GB HDD
@ http://phsw.atari.orgMy Atari stuff for sale - click here for list