Regarding Harlan Sharp - Again I made the effort to visit their Strongsville plant with blueprints in hand for some custom shaft-mount rockers I needed. I have found that these relatively small aftermarket suppliers are much easier to convince of your sincere desire to do business with them with a face-to-face meeting in which you lay out as many of the details of your wishes as you can. It really helped reduce their R&D costs and get the project in their line-up of jobs. Good luck.
