The original Wilburys were a group of 4 unique voices from varied musical backgrounds. Largely assembled as singers and not as players
I would suggest the roles as “The Kid” in Tom Petty (under 40 at the time)
“The Beatle” in George Harrison “The legend” in Bob Dylan
“The aged Elder Statesman” in Roy Orbison (Only about 50 at the time, but was about 40 years into his career. And only months before his death).
“The outlier/instigator” in Jeff Lynne of Electric Light Orchestra, Conceived the idea while producing albums for Tom Petty and George Harrison)