The document discusses options for retrofitting or rebuilding horizontal CNC lathes, vertical turning centers, and horizontal boring mills. It describes the mechanical, electrical, and control system components that would be rebuilt or replaced in the retrofitting process. These include new ball screws, electrical cabinets, wiring, CNC controls, drives, and servicing of parts like tool changers and tables. Retrofitting is presented as a way to upgrade older machine tools for continued use on aerospace, landing gear, jet engine, and other precision manufacturing applications.