One thing begets another, the Shads./Marvin influenced many groups and players of different genres. Even the Beatles recorded an early tribute.. 'Cry for a Shadow'. So it may not be folk, but the Shads. effect influenced guitar players all over the place, especially in Britain. Apache was originally played by its composer Jerry Lordan on the Ukulele. TBH anniversaries don't mean a lot. But those who are still around from that time, will no doubt feel very old!