Taking into account all the relevant factors the following Cherry varieties would be suitable pollinators.
AlbaluIn stockGroup ESelf-fertile A high quality Iranian acid cherry with strong cherry flavour excellent for jam and other culinary uses.
Bigarreau GaucherGroup ESelf-sterile An excellent sweet black cherry with a rich flavour and juicy texture
Black EltonIn stockGroup ESelf-sterile A very good black heart-shaped cherry. Very sweet and meaty/firm textured.
Bradbourne BlackGroup FSelf-sterile An old black Kentish cherry.
FlorenceGroup ESelf-sterile A large heart-shaped red on yellow cherry.
Merton LateIn stockGroup ESelf-sterile A very well flavoured red/yellow cherry, much like 'Amber'
MontmorencyGroup ESelf-fertile A high quality culinary cherry very popular in America for cherry pies and jams.
MorelloIn stockGroup ESelf-fertile The best known and most widely grown of the acid cherries in the UK.
NabellaGroup ESelf-fertile A high quality acid culinary cherry excellent for jams and pies
Turkish BlackGroup ESelf-sterile A small, sweet juicy cherry. Medium richness. Some bite otherwise lacking impact because it's small and does not have enough flesh.