Sonny was driving a 1941 car when he was killed at the tolbooth. But I now agree to you're timeline for the most part. I think it's meticulously researched.
Still, I strongly believe Michael returned to America in 1947 and probably didn't speak to Kay for yet another year. ("I've been back for a year now, probably more".)
"It was between the brothers Kay -- I had nothing to do with it."
