Those knobs probably wont work on the Harley Benton. They are for the fine spline (24 spline) pots like most CTS pots. Most of the pots in import guitars are coarse spline. I assume the Harley Benton has the coarse spline type.
Search ebay for the same style knobs for imports. I'm sure someone has to offer them. Otherwise, despite it being more work, you can always replace the pots.