These buttons remind me in their construction of some buttons shared by Pat recently: white base surrounding a blue and white patterned dome but branded as Beauclaire.
Another curiosity was the card itself: all my other Roger Berry cards have the coronet and name printed repeatedly all over the card … or so I thought. Re-checking I found this card I had recently shared:
I mentioned at the time that this was a Beauclaire button design. I think we can confidently claim that Roger Berry distributed Beauclaire buttons under it own label. Coronet was either a separate brand distributed by Roger Berry, or a previous label for General Plastics buttons before they started using the name Beauclaire in 1951.
These are all vintage Beutron buttons. The black irregular shape one dates from the late 1940s, the dark purple from the early 1950s. The gold are metalised plastic fromt he 1950s. I also have this design on a “Boil-proof Whites” card.