Yes, you need to build a kickstart 1.3 that includes the scsi.device from the 2.05 rom to be able to boot from an a600 ide interface on 1.3. The same thing would happen trying to run 1.3 on an A1200 or A600.
For 1.3 to boot from hard disk, it needs a device driver in rom for the hard disk controller. On a500/a1000/a2000 bootable hard drives that rom is on the hard disk interface card.
A600/A1200/A3000/A4000 had built in hard disk interfaces so their kickstart had the driver in them. Although if you added an extra interface (i.e. SCSI on the A600/A1200/A4000) then that too would have to have a device driver in it's rom to be able to boot from it.
An alternative can also be to use this:
http://aminet.net/package/util/boot/GetSCSI11Grab scsi.device from Kickstart 2.05 by using the supplied GetSCSI tool, and then create a boot disk with the resulting scsi.device file. Instructions are included with the package.
