A 19th century vampire-slaying kit containing a pistol, crucifix, rosary beads and four wooden stakes inside a mahogany casket left to a Yorkshire woman in her uncle’s will has been bought by the Royal Armouries in Leeds.

The box, which also offers a mallet and a bottle labelled “holy water”, is thought to have been made in the aftermath of Bram Stoker’s Dracula novel in 1897.

It is the first of two intriguing new acquisitions by the Armouries – the world’s largest and most powerful sporting rifle, which was designed to snare creatures on the scale of a dinosaur but has never been fired, will also go on permanent display at the venue’s Hunting Gallery after curators snapped it up at auction.

“These kits are often said to have been made as novelties in the Victorian period,” said Curator of Firearms Jonathan Ferguson, describing the two-tier vampire warder, featuring a percussion cap weapon with an octagonal barrel.

The crucifix and rosary beads were considered essential for discouraging bloodthirsty visitors. The holy water comes as one of three bottles, and the mallet and stakes are described as a “last resort”, accompanied by A Book of Common Prayer from 1857 and a handwritten Bible extract outlining how enemies might be slain.

“We’ve yet to establish a firm date for our kit,” added Ferguson.

“It’s Victorian in the sense that it’s made of Victorian components and intended to represent something from the mid-19th century.

“It’s 20th century in terms of when it was actually put together, inspired by post-Dracula vampire fiction.

“We will be carrying out tests to confirm the facts, but we know it will attract a lot of interest from our visitors.”

Organisers are hoping to show the kit at the Clarence Dock museum by the time Halloween arrives. The gun, called a 2-bore, should add to their arsenal in the meantime.

Made of British steel and decorated with a traditional English scroll engraving to mark the second millennium, the 26lb shooter was made in a lengthy building process by renowned English gunmaker Giles Whittome.

“When you pull the trigger, it’s like presiding over your own personal earthquake,” he warned.

“You want it right first time. I used to control elephants in Tanganyika many years ago with the Game Department.

“Experienced control officers would always tell me that, when being charged by six tons of angry elephant, any gun you are holding would appear too small. Well this gun is not designed to take down an elephant, but a Tyrannosaurus Rex.

“Only a reasonably fit and strong man can fire it safely. The biggest and best always fires the imagination – and this gun does not fail on any count.”

Wes Paul, the Chair of the Royal Armouries’ Board of Trustees, received the formidable weapon in a ceremony at the Tower of London.

“This rifle illustrates why British sporting gunmaking remains the very best in the world,” he suggested.

“Its design harks back to a time when, not much more than a century or so ago, large parts of the world remained unexplored.

“The adventurer, hunter or explorer would travel to these wild, remote and dangerous places prepared for anything that may endanger life, facing huge personal challenges but comforted by the knowledge of the quality of the technology at their disposal.”