Our Oldest Apple Tree

This is our oldest apple tree, it was well established when the previous owners moved in 47 years ago, we are not sure when it was first planted, but suspect it was self seeded when this property was unoccupied for a number of years.  The tree is currently some 40 feet high and is adjacent to my two workshops.  It had been considerably higher than this and about 20 years ago I cut off the larger high branches as I was frightened of them snapping off and damaging the workshops roofs, since then it has grown some new high branches.  This tree produces very small bright red apples that are very tasty, but I have no idea what type they are. 
 
Today is another day when I do not feel up to doing very much; I shall be glad when I visit the hospital next as they may actually do something, unlike my GP, who says there is nothing wrong.