Could be an interesting one to research Jarl - Heuer were all over the place when they were making these divers (or having them made), so it could be any number of reasons. I wonder if there were home and export variants. The German spelling is "Meter" too but they of course don't pluralise it as "Meters" so the spelling on the Autavia Diver bezels certainly looks to use the US English form. These days they would probably have a brand bible, stating what things should and should not be called everywhere in the world, but back then it seemed to be a lot more haphazard.

One of the things I like about the site is that you often feature the less common/more unusual watches (e.g. the Divers, the Rose watch, 3641 instead of Carrera etc) and I wondered whether this was a sort of "theme" for the collection? Whether you actively seek out the rarer watches? It's a nice collection whatever the motivation!