Issue 228 of MEW will contain a One Man and His Lathe article on Jon Freeman and his Chester Challenger.
Jon has produced a useful change gear spreadsheet for users of these lathes, you can download it form his website jons-workshop.com along with various other useful things!
You can also do a direct download of the spreadsheet with this link.
Many thanks to Jon and I hope more authors will choose to supply extra information in this way in the future!
Neil