I was a little surprised how small it was; the pictures I've seen look bigger. I used an unlabled vintage thread which I'm guessing was either size 20 or 30 and it was just over 3.5 inches/ 9 cm. It also took some coaxing to get it to lie flat with my tension; I was in a hurry blocking and it's still a little ruffly.

Then I tried another one with fewer picots so they didn't bump into each other (because I am Sarah, Remover of Picots!) and I think it emphasizes the shape better.

I may try a larger one as a small doily, per the excellent idea Batty Tatter shared (here) to enlarge the pattern by doubling the length of the arms.
I can only hope this book is reprinted, as it's a wonderful book of patterns but has become prohibitively expensive.