I think that a self declaration after a initial medical and ecg would be fine for PPL's up to age 50. After that a visit to an ame with ecg and biannually would do no harm. I have seen a few over 50 and slightly younger have ecg with abnormalities with hurdles to jump before getting class 2, in some cases life style changing. Self declaration for older folks seems bonkers to me, even if it meant an annual check with your GP. I have seen to many with eyesight and mainly hearing problems at 70+ when doing checkouts/LPC's.