Jose I must disagree
They did have aluminium in the 1930s-40 didn't they? So based on just the eye material how can be sure? The scalloped ferrule is way too fancy and the seamed bolster is a a pre 1940s feature which you never see on post WW2 examples which were usually made from spent brass shells
The seller does state that the bolo belonged to a senior citizen who who's father was a merchant marine so it is possible that the bolo could be circa 1935-42?