I'm not a button expert, but from my experience these style of buttons are from a "newer" two part construction. There is an obverse half and the reverse is made by machine stamping the shank outward. The two halves are then combined. Is there an opening under the shank that you can poke into the dome? If so that is probably what you have. If it is solid under the shank then it may be older and a better made piece. I am uncertain of a date when this style started, but I would think from 1960s or newer is most likely the age.
The first picture is blurry when I try to zoom it. The angle of the second picture doesn’t let us see how the shank is attached. I’d post better photos. Thanks. 👍🏼
The first picture is blurry when I try to zoom it. The angle of the second picture doesn’t let us see how the shank is attached. I’d post better photos. Thanks. 👍🏼