First, GREAT FINDS!
Second, being fairly new to this, I could be wrong, but...
The button doesn't look very professional, the design and the circumference look off. The only buttons I have found from that era, are done the same way, they were once round, I'm pretty sure. Then they broke, maybe just a corner off, and someone, being smart and frugal, reshaped and reused it! It looks hand carved. Which to me, just makes it that much neater. WTG!