Mark, if you really want to (or have to) keep the Dickson, and you can actually centre your cutting tools you might think of machining a new "stud" with reduced dia. for the end thread (s).
Steve
Steve
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.