With all this talk about 10mm pitch Shimano track stuff I thought I ought to add that Shimano did make - I have one - 10mm pitch sprockets to fit standard thread fixed hubs in addition to the special downsized sprockets and hubs. These are listed in the I think 1982 catalogue which also contains all the AX stuff.
Hilary Stone back in Bristol, England after having met a wonderful community of folk at The Cirque - SEE YER NEXT YEAR!