Three Bell & Howell 16mm Cine Projectors, a Filmosound 642, no lens, Filmosound 652, with Bell & Howell Super D Proval 2 inch f/1.4 lens, elements F-G and a Filmosound8D 652, Bell & Howell Super D Proval 2 inch f/1.4 lens, all untested, all would benefit from a clean, F-G