This Is Spinal Tap actors Christopher Guest and Michael McKean and the mockumentary’s director Rob Reiner have joined co-star Harry Shearer’s lawsuit against the film’s rights holder Vivendi. “It’s impossible that Vivendi’s income from music sales and merchandising totaled just $179 over a more than 20-year period,” director says In October, Shearer filed a $125 million lawsuit against Vivendi, …