>> My dads mother, Mrs Smith, had mtDNA haplogroup U5a, same as Cheddar Man. <<
And your father had the same haplogroup.
(You always get it from your mother.)
Well....yes. He had the same mtDNA as his mother but it stopped with him. He passed his R1b yDNA on to me. The U5a mtDNA of my grandmother is only passed down by the females.
I never knew Mrs Smith. I got her DNA from her daughters daughter, my cousin, long after her death.
My mother had a fairly rare DNA, haplogroup 'V', as do myself and 52% of the Skoat Sami people.