I actually think this could be a good opportunity to learn how to hex edit a save.

At this point, you can easily create two saves, nearly identical, but in different game years. You should then be able to compare the saves and find one byte that increased by one. Then, try changing that byte and see if it changed the year. In doing so, it shouldn't be too hard to find which byte you need to change to set back the game 60 years.

I'm still mad about this, lol.

Did you ever try the advice to modify the save file? Given the age of the game, I doubt it has many if any tricks that would complicate the approach that dtgreene suggested. That approach has the virtue that you do not need to understand anything about the game's file formats, and only need a very basic level of proficiency with the editor.