(10 Nov 2015, 7:45 pm)GX03 SVC wrote 7515/7516 and 7518 are all-route spares which carry MAX or Sapphire branding to avoid brand dilution. These vehicles do not form part of the usual allocation (route branded vehicles) unless they are operating extra capacity.
It can't be classed as a correct allocation as 7501-9 and 7522-8 are the correct allocation.
What about 6116/7 on the 309/10 then.