Dessert Apple tree

I wish we knew what kind of apple this is. It came from a neighbour of my parents where I grew up. He grafted many trees and experimented in his orchard. There are never many apples on the tree but they are very sweet and grow to be huge. When ripe they are pale yellow. The deer really love this tree and nearly killed it several times before it got taller than they can reach. I have not been able to match this apple to any photo and description I can find on line or in a book.

Dessert Apple tree
July 26, 2015