Interestingly enough I was speaking to an old boy at the Welsh BKA convention last year - a bit of an apple tree guru, has done a lot to resurrect a lot of the old Welsh marches orchards.
I have a few old apple trees in my garden (probably pre date the first world war) which have been neglected for fifty years or so, i've been tentatively pruning them to try and get some kind of order but one just needs too much work and the apples are now of a mediocle quality. his advice was forget the little and often pruning approach, just hack it right back, the shock usually makes the tree regenerate itself and you'll get fresh growth in no time at all (thinking of trying that with two of mine this year