Nothing wrong with the old designs even though they look a bit basic compared to modern offerings, it should be possible to reproduce the design and have the clasp function as intended, shouldn't need adjusting till it's several years old at the very least. Hopefully the manufacturer hasn`t skimped on the quality, some of the replacement bracelets thesedays have softer clasps than the originals, Omega are guilty of this despite the eye-watering prices for 1171 bracelets and the like.
The aim in the 60s and early 70s was to produce bracelets that were light, and watches that were slim, excessive bulk was frowned upon. Nowadays the opposite seems to be true and there's a mistaken perception that heft equates to quality.
I`m far happier with 60s and 70s watches, that's virtually all I wear thesedays.