Yes i know i am moaning but why did 73 get the A350 before 75 as this is the oldest 747 change over. I booked this to get the chance to fly on it, now i am sad i get the 330 which i waited for. I know its the luck of the draw normally. Moan over.
The boring answer is that the A350 is often switched in MCO with the LHR aircraft and the timing of the 73 allows for this. Also on Tuesdays and Saturdays the VS75 returns as the VS226 into EDI and this aircraft is A333 so the 75 needs to be the same.
On Wednesday and Saturday there is only one MAN flight which is the VS75 and on these days only it's A350 because the A333 is in EDI.