IT’S over 40 years since Enid Blyton passed away but the enduring appeal of her children’s books make the author as relevant today as she was back then.

Withstanding fierce competition from the likes of Harry Potter, even today Blyton’s generation-spanning stories regularly top the polls of the nation’s favourite children’s books.

The author is probably best known for her Famous Five series, although the Secret Seven, Noddy and The Magic Faraway Tree series also helped Blyton shift over 600 million copies worldwide.

However, that’s just the tip of the literary iceberg; over 40 years it’s estimated the prolific author wrote 800 books, which works out at approximately one every two weeks. And it looks like there could be more; this week an unpublished novel by Blyton was discovered in an archive of her work.

Mr Tumpy’s Caravan is a 180-page fantasy story thought to have been previously unread and was found among a collection of manuscripts auctioned in September.

The Seven Stories children’s book centre in Newcastle paid around £40,000 for the haul, which included Malory Towers and Secret Seven books.

“It’s really exciting,” said a spokesperson for the centre. “It’s all written with a typewriter and has no spelling mistakes.”

The protagonist in the book is a walking, talking caravan and while this might seem rather different from the ginger beer-swilling adventures of the Famous Five, Blyton wasn’t adverse to experimenting with fantasy.

“As in the Wishing Chair, an inanimate object is found to have a life of its own,” says Viv Endecott, who runs the Ginger Pop shop in Corfe Castle, an Aladdin’s cave of Enid Blyton memorabilia. “This time it’s a caravan with legs and a love of adventure.”

The typescript is not dated but it does carry the address Old Thatch, Bourne End, Buckinghamshire, where she lived until 1938.

“It was probably written in around 1938,” says Viv.

“It has aspects of her other fantasy books that were written in the late 1930s.”

Blyton was a regular visitor to Dorset and spent many summers in the Purbecks, so could this previously unread novel have Dorset influences?

“No,” explains Viv, sobering our excitement at a new Enid Blyton link.

“This is way before her Dorset period.”

However, the county was the muse behind some of her other books; Kirrin Castle is popularly believed to be based on Corfe Castle, Whispering Island is based on Brownsea Island and Mystery Moor is reputedly set on the heath between Stoborough and Corfe.

And lest we forget PC Plod, the rosy cheeked bobby in her Noddy books who was based on the late PC Christopher Rone of Swanage.

“The world’s most famous policeman was a rural Dorset local copper,” says Viv. “I can’t help feel that the British policeman has got such a good reputation abroad because of PC Plod.”

• All this week, The Surprising Caravan will be read at story-time to visitors to Eileen Soper’s Illustrated Worlds on Poole Quay. This is the interactive attraction which brings to life the amazing work that Blyton and Soper did together, and the era they lived in.

Eileen Soper’s Illustrated Worlds opens daily from 10am.