Thank you Gene, that's interesting information. Every time I see a '49 Chevy, Olds A body, or Buick B body, I'll have to check for the early vs late trunk lid!
First i want to say that I saw only one 1949 with the early lid when they were new in 1949.
In 1949 several GM cars revised the shape of the lid from rounding down to a more squared off shape..
I never saw a reason for this other than giving the rear end a more modern loook and it did inrease the room in the trunk slightly..
I did see more early 1949 A body Oldsmobils with the rounded lid as well as B body Buicks.