DiagBox v7 final release was v7.77, and DiagBox v8.01 corresponds with v7.65, you can find this information here:
http://service.citroen.com/dtt/IFD/AC/documents/fr_FR/
But DiagBox 8 had newer engines (probably to enable new functions and remote services which will be introduced later). Another change was at 7.72/8.08, where the locale coding standard was changed from 2 chr$ to 5. This is why changing language from the menu does not work, I have explained this in one of the posts last year.
DiagBox 7.83 corresponds to 8.19, which I released for DiagBox 7 last year. But in the case of DiagBox 8, I stopped at 8.17 because this is the level where I could use the full ******* updates without removing anything from the original files. The same applies to the APP_8.17-8.42 updates, they are all full updates with nothing removed.
If you install 8.01 and update 8.02 and I think up to 8.10 (as far as I remember), you can use (relevant) maitresox updates to reach 7.83/8.19. Because all updates from 7.67/8.03 are ******ly identical.