I have seen an original one from H&H and the rotor was modified with ball nose cutters but there is a limit to how much can be altered, which is why the cartridge has a very long neck as it was designed around the machining limitations of the rotor. The action is also modified and while they used the 1903 action to start with they very quickly switched to the 1905 action when it became available as it is wider and there is less machining required.

Matt.