Like Hugo, I have never heard of this camp and I lived in Colwyn Bay c1968.
Al Stevens must have been well known as he appeared on BBC Children's Hour in 1954. This link mentions him if you scroll down to 17.00 on it.
https://genome.ch.bbc.co.uk/schedules/bbchomeservice/basic/1954-12-28I found this as well:
https://www.ebay.co.uk/itm/CAT-impersonator-ORIGINAL-POSTCARD-AL-STEVENS-CREASED-BOTTOM-LH-/142604502671I imagine the sale of the camp would have been reported in the local press at the time.
From the death of Alfred Stephenson I note he was born in 1924. That means Winifred would have been born around that time. Do you know her year of birth please?
There are two deaths for a Winifred Stevenson which are possibly for her:
Liverpool RD December 2003, Winifred born 04/01/1926.
Manchester RD December 1999, Winifred born 23/02/1927.
There is a possibility that Winifred remarried have you searched for that? Do you know where she came from originally?
The street and trade directories for Old Colwyn/Colwyn Bay might have entries for her at that time.
I look on Genes Reunited to see if anyone had Alfred in their tree and one lady had Alfred Stevenson born Manchester 1924 on it.
Helig.