This is the former K-3071 that was converted to ground instructional airframe after its crash on 2 October 1973. The letters NAC indicate "Nico's Aircraft Corporation" after the two technicians who restored the aircraft and who apparently both had Nico has their first name. The aircraft was scrapped in 1998. Photo by Martin vd Sluijs.
This photo was added on 14 February 2023, and has since been viewed 300 times.