WGS 95 had DDS1 drive but you can probably install a new DAT drive but then you have issues with the LED placements of the bezel and maybe the eject button.
You are right, I was only interested to buy one in order to "complete" a 840av (I found the appropriate front bezel), using it for backup purposes with Retrospect.
I used to use a similar setup (substitute a DDS3 external SCSI HP unit) for my Macs, until my hobby got out of hand. Retrospect was excellent for that. I still have some of those old backups ...now if I can only find which box I packed away the tape drive in ;-)