Help Please Watford Electoral Rolls...

[Dale]

Kia Ora
Greetings from New Zealand.
My great gran emigrated to New Zealand in 1878 & I am trying to track her family "forwards" from 1901.
I have ;
John Francis Robert James WILLIAMS born Jan 1895 in Rutland living in Watford in 1901 with parents Elizabeth Mary & Henry John WILLIAMS & Siblings: Arthur Richard, Violet Lizzie Swinton and Henry Burgess WILLIAMS.

I know JFRJW died in Wales in 1989 and that he was a retired printer but there is no sign of a wife or family and I had no indication what he did between 1901 and death until  today when I received a death cert  for his aunt! He was the Informant.

On 26 February 1954 he was living at 10 Hazeltree Rd Watford.

Is there a kind soul who could look at Electoral Rolls about this time to see if there happens to be a wife, partner, lover, children, siblings or whatever at the same address? He would have been about 59/60 years of age. His parents were killed at Teignmouth in bombings of 1942

What else will the Roll tell me?

Can anyone tell me anything about this address?

Where should I write to get the information?
Any clues at all gratefully received

Thanks
Marlene