Actually I hadn't thought about Denis.
The census says his Mum was Elizabeth and she was born in Wales. Probably in Dowlais too.
His Dad was Daniel Collins.
I should be able to get them on Free BMD.
I have to wait another week and a half before the LDS family centres are open again here. then 2 weeks til films arrive after that.
I am happy for you to take a look at the family but I have absolutely NO info on the generation further back.
Maybe its Moaxly/Moaksley marriage but its just a guess.
You all probably know how the naming thing works in families, so you might be able to work out from the sons what John Collins father might have been named.
They named the first boy after the grandfather, didn't they? Trouble is they lost a couple of kids.
1911 census says they had 9 children born alive but only 7 living in 1911.