Dipstick mark to mark is 1L so not sure how you managed to measure 1.25? Do you mean 1.25 marks on the stick? I which case that would be 250ml....
Apologies, I should of changed my wording - I didn't bung in the full litre at the service station. I added 250ml on the hard shoulder and then added about 350ml at the service station. The dipstick was then registering full (left it to settle for 5 mins before checking)