The Brass roller does not turn, when the locking set screws are tightened. Whats interesting is that all these different makes fit other tools ! these days everyone makes there tools so that no other manufacturer will fit. I did wonder why that roller wouldn't turn, to me the engineering was there, unless there is a washer /spacer missing. Is there anyone who can give me the heads up on how to sharpen this Nicely. My idea was to get a 1000/6000 king water stone and use a circular motion then simply put strop. I have sharpened chisels etc before but no leather tools...Should I be scared !! Anyone in London that wants to help let me know. Thanks again.