Someone asked me if I had such a freewheel. It's not for me or for a friend, just someone who saw me bid on another Sachs freewheel on eBay. If you have one you would like to sell let me know, and I will have them email you or give you their address. They didn't ask about the cog I just thought I would check on that, too, so if you have one let me know. Maybe they could do a transplant.
I personally would like to know of additional sources for individual freewheel cogs for Suntour, Shimano, and Sachs. I know loosescrews.com and harriscyclery.com have a few. I am sure there are other sources. Any suggestions?