They still need a drummer. A sequel to “This Is Spinal Tap” was announced Thursday, and all four major characters are set to return. Rob Reiner will return as the fictional and actual director, while Michael McKean, Christopher Guest and Harry Shearer will once again star as “one of England’s loudest bands,” Deadline reported. However, their drummer has not been announced. The follow-up to 1984′s beloved mockumentary is scheduled to premiere March 19, 2024, just over 40 years after the original was released. Reiner, who debuted as a director with the original film, said the sequel will be base…