There seems to be a couple of problems. Back in the '60's , although abhorrent, it seems that casual "touching up" was commonplace and was mainly brushed aside by the "victims". There were quite a few cases when mini skirts came in of men being let off such things when, for example following a mini skirted girl up the stairs of a bus. Totally wrong then and these days even more unacceptable. My wife was a Theatre Sister in those days and the behaviour of some surgeons in the operating theatre sometime resembled "Doctor in the House", for example.
Of course abuse of minors, however long ago , as in Saville, must be pursued. The sort of "1960's" episodes are difficult to prove after such a long time, so it is difficult for the Crown Prosecution Service to decide to go ahead or not. The people who have been found not guilty have admitted that they were not angels, but in the light of '60's norms were probably not unusual, however unacceptable by todays standards. Maybe if found not guilty they should be able to recover costs.