I received some offers offlist and have bought some cogs and an FW and may still get a few more.
The CR member I bought the lot from thinks two of the three 11-13 combos are NOS and pretty rare. I think these would be used for Ultra-7. The 13 threads onto the FW and the 11 threads onto the 13. I also have three 13-12 combos - those are excellent but not NOS. I'll trade any of these 2-cog combos even up for a 14T outer, or sell them outright for $10 for each 2-cog combo.
BTW, furthering my education about SunTour FW's it appears that Perfect and Pro-Compe also had middle cogs threaded, but inners tabbed. And 21T seems to have been the largest threaded cog for Perfect and Pro-Comp as well. The important difference, however, is that Perfect and Pro-Compe accepted three tabbed inner cogs, rather than two, and a couple of variations may have even accepted four tabbed inners. This made those models more suited to wide range touring FW's than the Winner. It also appears from Sutherland's that the Perfect, Pro-Compe and the Alpha, an 80's replacement for the Perfect, were sold with Ultra-6 spacing in the early 80's. I've only seen Ultra-6 on New Winner and Winner Pro. It may be that there was some interchangabiity between Perfect and Pro-Compe and Winner cogs, but I haven't confirmed this
BTW, I disassembled a couple of low-priced recent FW's just to see if their cogs might work with Winner. One was a Taiwan-made Sunrace 6-speed, another a Nashbar-branded Chinese made 6-speed. No luck. These recent FW's seem to be made like cassettes, with all except the outer splined similar to cassette cogs. The Taiwan made Sunrace had a threaded outer cog, like most high end classic FW's. But the Chinese-made Nashbar has all cogs, including the outer, splined and the wole thing is held together by a lockring similar to a BB lockring, but much thinner. I could not remove the lockring with a BB wrench, in part because the lockring was too thin to give good wrench purchase. The only way I could get the lockring off was with a hammer and drift punch. Is this construction common on cheap Chinese FW's? Is there a lockring tool that works for these? Somehow, I don't consider as acceptable quality any bicycle component on which routine maintenance has to be done using a drift punch. Of course, one probably rarely does maintenance to these, as having the cogs changed out at a shop would no doubt cost more than just buying another cheap FW. So I guess these low end FW's have become throwaway items.
Regards,
Jerry Moos
Big Spring, Texas, USA