“Sometimes it feels as if we are on Dragons’ Den every day”Charlie Bunker and Gabby Vautier of imPOSSIBLE Producing are on a mission to create a ‘South West End’, developing an ecosystem of talent based in and around Cornwall that can form a pipeline to the rest of the country. Lyn Gardner meets the pair as they prepare to stage their first musical, The Creakers, which will play at Theatre Royal Plymouth before a run at the Southbank Centre in London