WELCOME ABOARD!
There is a mod that gives German on the instruments. It's a stand-alone, and I don't think any of the ones you list changes them to German. I'm not sure how they got that way, and I'm not sure to get them back.
I know it won't help now, but a word of caution for the future: Always keep a copy of the entire stock Data folder in a safe place. When something like this happens you can find the file and replace it.