One thing I noticed in the datasheet of the Sil3112 is that the very end of the flash chip is supposed to contain some initialization values that the Sil3112 will read.
The ROMFILE.1S2 file doesn't contain this info. I find this suspicious. Maybe the updater program puts it in and that's the missing piece of the puzzle. The WiebeTech firmware file has it, but it wouldn't actually be at the end of the chip on your card because you have a 512 KB chip and the WiebeTech firmware is only 64 KB in size. We could try making a 512 KB ROM file with the correct info at the end, but I don't know what that info is supposed to be on your card.
It's also possible that your card has a serial EEPROM that it gets that info from instead...but I don't see it in pictures unless it's on the side of the PCB opposite the Sil3112 and flash chip.
The ROMFILE.1S2 file doesn't contain this info. I find this suspicious. Maybe the updater program puts it in and that's the missing piece of the puzzle. The WiebeTech firmware file has it, but it wouldn't actually be at the end of the chip on your card because you have a 512 KB chip and the WiebeTech firmware is only 64 KB in size. We could try making a 512 KB ROM file with the correct info at the end, but I don't know what that info is supposed to be on your card.
It's also possible that your card has a serial EEPROM that it gets that info from instead...but I don't see it in pictures unless it's on the side of the PCB opposite the Sil3112 and flash chip.