Help understanding 200M Pre-Bonds

I really like these watches. I have never been a fan of the Bond era divers. The HEV while a beloved feature for many has always put me off, never got on with the wave dials either. It is a bit of a shame because Omega QC was not always perfect in the period these watches come from and sourcing specific parts for the movements can be a challenge.

Still for the heritage, brand equity, style and connesiuer points, I think these are a worthy pickup!