The first thing I would check is that it is actually the slave on the first connector (which is what scsi.device unit 1 will always be) and not master or slave on the second (as you are using idefix I am guessing you have a buffered IDE interface), if so then the second connector is scsi.device 2 (master) and 3 (slave)
Also if you have the emergency disk for 3.5 copy its devs/dosdrivers over to your harddrives devs:dosdrivers and it should mount.
