The larger card is perforated so that the four buckles could be sold separately. I have this on a Cygnet branded card. I think that both Cygnet and Walkers products ( as well as Delphi) were manufactured by D. C. Quinn P/L in Leichhardt, NSW.
I can’t make up my mind if the buttons on the right are MOP or a clear imitation using marbled polyester.
Cards of buttons of this, the most common size (approx 5.5 x 9cm), can carry any where from one to nine buttons. Usually they are of one size, but sometimes there are 2 or 4 smaller but matching (cuff?) buttons.