Answer: You can probably save them and bring them into health with a little care and patience. Neglected trees can be pruned over the course of several years to bring them slowly back into shape. Do not rush the pruning, as too much at a time can shock and damage the trees. Also, home trees often do not need the type of severe pruning we see done in commercial fruit orchards. Keep in mind too that the trees may be different kinds with different types of apples, or one may be serving as pollen source for another so be cautious about removing any of them -- or nearby wild apple or crabapple trees as well.
If they are in full bloom then they are at least vigorous and potentially very productive. Apples can live for over a century so age is probably not really an issue. New trees could take five years or so to become established and begin to bear a light crop so working with these trees is probably a better bet if they are healthy.
I would suggest you work with your county extension to develop a spray program based on local conditions. They may also be able to help you evaluate the trees.
As far as pruning and general care, you may find the following helpful. You may need to cut and paste the complete url into your browser to make it work correctly.
Enjoy your new property!
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