This is probably a long shot but this clipping came with my MGJ2 J3201. John Buchanan owned the car from 1968 - 1982. I believe this was taken in 1970. Has anyone heard of this classic car event at Monza?
According to Motor Sport, April 1961, previewing the third Coppa Monza, it was run by the Club Milanese Automotoveicoli d'Epoca, who are still very much in business: