Farmer Frank - WNC Old Apple Tree Revival

Good day all.  I recently discovered this site and what a wonderful find it has been!  What a fantastic community to learn from!

We are under contract on a farm in WNC and hope to settle in later this summer.  I will definitely be adding other posts in the future but in my first topic I'd like to get some opinions on this old apple tree that is near one of our outbuildings.  Based on what I've learned so far, my first task should be to trim all of the dead branches from the canopy but after that is there anything else i should do to revive this tree?  It has likely been standing at least a couple of decades and has not been cared for at least a few years as the farm has been vacant.  

After trimming the dead stuff should i just let it be?  
Would it benefit from a deep root fertilization, or should i just start covering the drip line with mulch or wood chips (not covering trunk of course), and then letting the chickens browse around it to fertilize?
Does anyone have any creative ideas around how I would determine what kind of apple tree it is?

I've attached a few photos but can add more if someone would like to see more detail.  

Thanks all!

Frank

Welcome to permies Frank!

Until the real experts show up, take a look at this thread: https://permies.com/t/77639/sick-apple-tree-orchard

Among subjects discussed is how much living wood to remove in a single season. Good luck!