2,5-7,5 ml lime juice depending on the sweetness of your orange juice (and your taste).
In addition, the style/perception of the cocktail changes a lot...
Note of 31. december 2023: drinking Mary's Jingle listening to the Danish Queen's surprise annoncement of her abdication and crown princess Mary to become Queen Mary. Perfect cocktail timing.
I served the cocktail at my New Year's party, when we all were listening to Queen Margrethe's traditional New Year speech at 6pm. It happened to coincide with the Queen's surprise annoncement of her upcoming abdication on the 14 Januar 2024 - and consequently the new King Frederik the 10th and Queen Mary.