Considering the age & height of the tree, I don't think that pruning it now, especially in the top half, will produce the results you're looking for. I can't clearly see the whole tree from the ground up in the pic, but it doesn't look like it has been pruned into a low-branching orchard style tree in its past. If you start removing a lot of
wood from the top of the tree, you will be signing up for climbing up there every year to remove hundreds of
water shoots, not to mention just stressing out the tree. If there are huge dead branches threatening to fall down on something however, definitely get rid of them.
I'd agree with Patrick's recommendation: adding lots of compost and companion plants, It will just help to strengthen the tree and prolong it's (still probably rather short) life. As for the birds.. free
poop for your garden!... and for the tree for that matter.
I'll also throw in my opinion that lichens are not a bad thing for a tree...
As for the moss... do you ever have any irrigation sources hitting the tree, or is it just wet where you live? I've seen trees that have been pounded by sprinklers with very aggravated fungal symptoms.
You could always plant some cherry pits, and experiment with grafting whips/buds from the old tree once the seedlings are big
enough. Then you'll maybe get another 60 years out of it!
The apples: do they show evidence of a history of regular pruning? eg. lots of old branch scars or an 'umbrella' type shape? If so, they would fruit better if returned to that shape. If no, same recommendations as for the cherry.
If your research is correct regarding the age of all of these trees, fruiting naturally declines as trees reach the end of their life span. However, as the trees actually begin to die, you
should see abundant fruiting in a last desperate attempt at procreation!