<p>➀ The article details an investigation into the safety interlock system of a 1985 Denford Starturn CNC lathe, revealing factory wiring errors and voltage rating issues in components like relays and logic ICs;</p><p>➀ Unexpected discoveries include the availability of original 40-year-old connectors from RS Components and a reversed speed control potentiometer due to incorrect factory assembly;</p><p>➂ The machine's design evolution is analyzed, highlighting ad-hoc modifications (e.g., external stepper drivers) and safety concerns with mixed mains/logic voltage traces on the PCB.</p>