First of all, the roms in AF are encrypted, so you need to load them into a WinUAE-enviroment and extract it either with a command in the enviroment or connect Amiga Explorer to it and get the kickstart out. Load the exact same version in WinUAE as you have already a superkickstart of. Then you can do a byte by byte comparison with the superkickstart you have. I opened them up in Funduc Software Hex Editor for example. An ordinary 512k ROM ends with offset 524287=0x7ffff bits=00011111 unsigned B:31 (1f). Last four bits: "00:1e:00:1f". Now open up the superkickstart version of the same version and go to the same offset. You will find the "00:1e:00:1f" in that too, however that's not the last line in it. The rest following it until the end is the "bonus code". I just used that bonus code and cut and pasted it into a 3.1 (40.68) at the end of it. The resulting file should be 526 572 bytes.
