No they are not related, i thought that, but i met Eoghan in Aberdeen and I asked him and he said no, so what can i say you would think so.
Also his name isn't Eoghan Quinn, it's Eoghan Quigg, which...
To the best of my knowledge ..Nothing.. Duncan was a" No Talent " and basically a jerk as a young man.. maybe he grew up.. .. His Father gave him a bit part in Caravans.