Louisa - have you thought to keep a diary as to your life - how much you miss them, write a little note as to why you left for when they appear at your door. I am sure that eventually curiosity will over-come anything that their Father has fed them ; …… Could you send a note to each via their GP Surgery? At least the Surgery will be aware of how you would like to have contact and also, why any problems are 'there' that the GPs may be involved in ;-).
You could put a big 'item' in the local papers: Western Mail and Cambrian News for starters? "Hi A/B/C - Mum here, thinking of you daily despite the difficulties over the years. I wish you well on your birthdays date/date/date …….. I wish you good health and should you be curious about any medical history that might affect your future, do get in touch"
Or perhaps via the Salvation Army who can track people so that you can info. and can contact when they are ready.
I HATE C.mas because of bad childhood memories and associated anxiety =
