Only 50 people were allowed to go to his funeral due to Covid but "tickets were hotter than a Coldplay concert" Rob joked.
They received at least 100 sympathy cards, from "Oxford University professors, to politicians and the unemployed".
After his death, a new £1.6m wellbeing centre attached to Glenwood Church in Cardiff was named Lockwood House, after Ronnie.
But the old building and the new building didn't quite match, and they needed extra funding to finish the renovation.
"But they needn't have worried," said Rob.
"Almost to the penny, it was the exact amount Ronnie had left in his will.
"In the end the homeless man put the roof over all of our heads."
"Isn't that amazing, I just think it's all meant to be," said Dianne.
"People say to us, how did it happen - 45 years - but the honest truth is, in some ways, it happened a day at a time.
"Ronnie brought a richness into our lives."