Play Older Versions of the game

[Purelmagination]

I've been trying to get pathfinder for around 2 years now. Unfortunately, I don't play often enough so these new map updates reset and delete some of my progress more than I'd like. It is possible to manipulate the steam files to play in 1.0 or 1.1 and still allow for achievements to continue to unlock and/or permanently disable updates?
Thanks for any insights!

[Reese]

The oldest version of the game found on Steam(at all, not just players), is 1.26.

One thing though, you can simply uninstall DLC content to make the map smaller, or use a standalone map mod with less road and get 100% in that for the achievement.

[room217au]

You can select "versions for mod compatibility" from ETS2 properties on Steam.
eg. You can 'roll back' to 1.43 and still enjoy the improvements to that point, but the game will never update and new achievements won't be available.
The most important thing, while the game versions go way back, the number of branches allocated for those versions is finite.
What this means is that eventually the last ones on the list be be removed.
And removed without notice.