1960's Parker 75 Insignia: fine crosshatch pattern, early USA model with flat ends, marked "14K G.F," (gold filled, not gold plated as were later 75s), section with angle indicator, 14K nib with "66" on feed. Uses standard Parker cartridges or converter (metal squeeze converter included).
Used, cleaned from old ink. Converter in working order. Show some minor signs of use. Condition as shown in the photos. I believe that nib tip is M size