Producers of a stage adaptation of Happy Days are calling on fans to invest thousands of dollars to cover unexpected expenses.

Happy Days - A New Musical is already fully funded but bosses are seeking a further $375,000 (£250,000) to cover unforeseen costs before it starts touring in January (14).

Producers are hoping fans will be tempted by the involvement of the original Arthur 'The Fonz' Fonzarelli, Henry Winkler, as creative consultant and the Tv show's creator Garry Marshall as its writer.

But investors contributing money via the crowd-funding platform run the risk of seeing no returns on their investment if the show fails to turn a profit.

Director Martin Campbell tells Britain's Metro newspaper, "There is a risk attached, but this time the show is already funded and this is a way to gain engagement with Happy Days and musicals fans who want to buy into something they love or diversify their portfolios with something fun."

The adaptation, which stars Sugababes star Heidi Range in the female lead, opens at the Churchill Theatre in Bromley, London, in January (14) before a national tour, with a West End stint planned to follow.