I have a legitimate cps1 sf2ce japanese pcb with roms that had yet to be dumped. My first eprom programmer wasn't dumping the roms correctly so I bought a cheap willem. The willem took a lot of effort to get working, I also had to buy a 40 pin 16 bit adapter for the willem to be able to dump the 27c4096 eproms that were needed for the game to play.
The software cd that came with my willem never worked so I did internet searching and found out my willem is the revision 3 pcb. I downloaded the best software I could find for this pcb. I had to go into my bios and change my lpt port to "ECP+EPP" mode. Any other mode and the willem wouldn't dump correctly. After I successfully managed to dump a nes game eprom and get it running in an emulator I decided to attempt dumping my undumped sf2 pcb.
Unfortunately the willem software doesn't tell you if there's a bad pin connection anywhere. I had my sf2 eproms sitting in precision sockets to protect the pins but using the sockets caused some of the pins not to connect giving me bad dumps. The bad dumps didn't work in an emulator so I took my sf2 turbo pcb which is already emulated and dumped a random 27c4096 eprom from the pcb and copied it into the zip for sf2 turbo and the dumped rom worked fine in an emulator. Since sf2 turbo was a cheap pcb I just stuck the eprom into the programmer without a precision socket and this gave me a perfect dump. So this proved that atleast my willem was working right.
I tried redumping my sf2ce eproms without the precision sockets and sure enough two out of three of the dumps had different crcs from previous dumps. After each dump I took the chip out of the programmer, put it back in, dumped again, and confirmed that the crc was the same. After getting everything dumped properly I copied the dumped images into the zip file of the US release of the same revision and the game ran fine in an emulator saying "japan" meaning that the dump was a complete success! Here's the zip of the dumped japanese street fighter 2 champion edition 920803 roms:
http://www.mediafire.com/?hw8j15e8e4rhtay
You'll also need the sf2ce.zip file which contains the rest of the rom data the game uses but it's easy to find on the internet. I tested this dump in winkawaks and it worked great. In winkawaks or any emulator the game will be listed as "street fighter 2 champion edition 920803 US" but once you load it it'll say "japan". The reason why the emulator doesn't liste it properly is because this revision has yet to be added to the emulator list since I'm the first person to dump it.
I realize that this could be considered as piracy but the game is so old it shouldn't be much of an issue. It's quite fun playing the game in japanese mode so I'm just glad that now other people can share the same experience.