Re: 'The former would surely have been to young'
"1925 / 1930 / 1937 - Burton / Harris / Hopkins. Not huge gap..."
You are quite right. I guess I think of Hopkins as younger because his career got a second wind in the late '80s by which time Burton was dead.
Reading the Juggernaut plot summary rings bells for me. The cast is impressive including Bilbo Baggins and Roj Blake.