Hi Andrew, I have the use of a Box-Ford A, but I have not done any screw cutting on it. The gear on the thread cutting dial has been chewed out by the lead screw, why the heck do they put a keyway down a lead screw, I don't know, my Taiwanese lathe uses a separate shaft. At least I know how to cut threads without a dial, learned that nearly 60yrs ago at school.
Ian S C