It is really hard to date a button without the backmark or the back.I will post a link with several
Navy Buttons,you have to look close cause there are several different styles with very little differences.
Look at the eagles head,the top star is close in some and a little further away in others.Look at the pointed end of the anchor is it in front of the wing or not.Does the other end of the anchor go all of the way to the edge
rope border or stops before it gets there.Like I said there is some differences from button to button.
Also they still make and use that button on some modern blazer.No matter what I still like finding
buttons like that.Congrats