The "7.5 Megs ZIPs" (probably fast RAM) indicates that the machine in question is a SuperKickstart machine which actually boots the required Kickstart from harddisk prior to loading Workbench.
- Do not delete/format the system partition unless you have a SuperKickstart disk! You won't be able to boot from a Workbench disk before Kickstart is booted.
- You can select Kickstart 1.3 on cold boot (hold down both mouse buttons), no need to soft kick it.
- AmigaOS 3.5 or 3.9 require 3.1 Kickstart ROMs (it's possible to superkickstart 3.1, but you'd have to buy ROMs anyway in order to make legal use of it).