2.1 imperial pints or about a litre. I'm guessing but I think I put less than one third of a litre in. Guessing, because this was happening on a busy service station forecourt, and when I had pumped quite a bit in I checked and the box was full and there was at least a third of a litre on the ground. If you've ever filled a gearbox you'll know how this happens. And there is still a third of a litre in the bottle.
I did the last gear box oil change and filled it about two years ago but I had not checked it since. Maybe thrashing it around Le Mans for two laps has caused an issue.
