I've been prepping these (probably new old stock) shoes - had to have brittle heel caps replaced - and have been picturing them closing with a ribbon or cord tie. Today it occurred to me that there might have been a flat buttony thing (great technical terms, hmm?).
They're a little too small to try on a human foot here at Chez MagsRags, but I will say that visually, I can picture a foot inside more easily with the two sides meeting than with them overlapping.