I've search a lot for this.... because i already made my a3000 boot from 3.1 or 1.3 on the start menu, but lost the 1.3 devs:kickstart files.
last night i found that makefiles (under the Tools folder of the a3000 install disk) will do the job on a superkickstart disk to add that #?%#&@ bonus code to the kickstart file.
ex: makefiles df0: 1.3 devs:kickstart1.3
put that files in WB_1.3:devs/ and rename kickstart
same thing with other kick i suppose (on WB_2.x:devs)
Hope this is good for you! Here it work!