In terms of timing, your watch would be more of an E-6 with the earlier tachy scale - you'll see in the introduction to section E that there's a note about the two different tachy scales being used interchangeably through a good part of production (i.e. the 50 to 200 tachy wasn't discontinued after the 60 to 500 scale was introduced, unlike the earlier manual Carreras).

We tried to see if this could be used in dating but all we could be certain of is that the earliest production only used the 50 to 200 scale - after that (and not very long), it's more or less random which scale is used. Indeed, one of Heuer's catalogues featuring the manual Carreras has the 5 manual models with tachy scales all mixed up too. It does stabilise later on in production.