Val, aged 93, has generously bequeathed the private collection to Pembrokeshire County Council, which will create a new permanent gallery suite to house it at Scolton Manor, the county museum.
The collection was built up over many years by Val and her late sister Pam, who grew up in Surrey and Sussex together before moving to Newport in later years.
It was inspired by the discovery of a childhood treasure of Val's - a dolls' house called ‘The Gables' which her parents gave her for Christmas 1932, when she was eight.
"I'd been hoping for a dolls' house, and I'd been eyeing up a wonderful one in the Harrods catalogue, but it was rather big and I didn't think I'd get it," recalled Val.
"I couldn't believe it on Christmas morning when I saw this huge present waiting for me to open!"
From then on, Val played with the house constantly and saved up her pocket money to furnish it with miniature items, with birthdays and Christmases bringing more tiny gifts from family members.
But in July 1939, Pam and Val's father took a commission in the Royal Artillery and the family house was let. The dolls' house was put into store ‘temporarily'. But eight weeks later came the onset of the Second World War and the house remained in store for the duration - and was then forgotten about.
It was only after their mother died in 1977 that Val and Pam found the dolls' house in the attic of their parents' home, perfectly preserved in its original storage crate.
Not only that - they also found their mother's dolls and toys dating back more than a hundred years, and their own childhood treasures.
"Imagine unpacking those!" said Val. "It was a magical moment. And I'm afraid my sister and I were off collecting!"
Over the following years, Pam and Val built up a famous collection of dolls' houses of every period from 1840. Each house is furnished only with items produced at that time, and offer an intriguing glimpse of family life at home.
"We deliberately collected houses from every era," explained Val. "Individually they're not so interesting, but together they present a complete social history from the early Victorian era onwards."
The sisters also sourced miniature toy stables, shops, theatres, and many toys and games - including rare vintage mechanical toys.
In 2010, the sisters opened the collection to the public for the first time at ‘Ty Twt' in Market Street, Newport.
"It's quite funny seeing fathers coming in with their children, because you can tell they're not particularly into dolls' houses," said Val. "But by the time they get to the WWI house, they are really interested and telling their children all about the things inside!"
The collection has featured twice on the BBC's Antiques Roadshow and includes treasures such as a miniature dog which once belonged to Margot Fonteyn, and doll dresses given to Val from her childhood friend's father, who happened to be Gone with the Wind star Leslie Howard.
It also features ‘St Edwards Junior School', a charming teddy schoolroom created by the sisters when they were children, saving their pocket money to buy the tiny teddies at nine pence each.
Cllr Paul Harries of Newport, who was instrumental in bringing Val together with the Pembrokeshire Museum Service, said the collection was a ‘real treasure'.
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