Posted: 11/08/2017 at 14:43
That looks a bit like ripe Marjorie Seedling plums. I used to have a very, very large tree when I lived in Hertfordshire. (when I say large - we picked 1cwt in an afternoon - and that was just the plums we could reach).
If so, you are very lucky. Fully ripe they are a super dessert plum. Slightly firm they are wonderful for cooking in plum pies and crumbles. Any others make nice jams and chutneys. They make a rather thin wine, which is a difficult one, actually, because the skins can make the wine difficult to clear.
They also freeze well. I used to halve and stone them, layer them in polyboxes with a sprinkling of sugar over each layer.
PS our neighbours helped us out with the largesse that we picked, thank goodness, or the freezer would have been full of nothing but plums t