Mystery Pear Tree: #P11F Possible Clapp's Favorite?

Tree Type: Pear, dessert/cooking
Harvesting Date: Mid to Late October
Location: Whitmore Lake, MI (F)
Approximate Tree Age: ~50 years
Tree Status: Possible antique orchard remnant
Possible Tree Varieties: Clapp's Favorite? This is a tough one to figure out, but it's got a very thick neck so I should be able to get it eventually. 

Fruit size: Medium
Shape: Classic with undefined neck
Fruit color: Creamy yellow, with russet spotting when ripe. Some south facing fruits had slight blush to them.
Skin: Thin, slightly tough where russetted
Flesh: Light cream to white
Additional notes on appearance: When unripe, the pears have a very green color to them. These pears appear to ripen on the tree without falling until overripe. 

Taste: 
Texture: 
Additional notes on taste: 


Disease/Pest notes: Obviously a very old tree, but had minimal disease. Tree was tall and scraggly which probably improved air circulation, preventing most fungal diseases.