Oh, you know, since the letters in Trier are both in German, maybe this letter will be in German too, and then we'll have it made!

Btw, if you want to start practicing on Fritz, Wilhelmine, and some other siblings, this site has both facsimiles and transcriptions for you.

Cunning plan:
1) You work on getting the hang of the handwriting.
2) We wait for lockdown to end and order the letter.
3) Profit!

I've only studied old roman, early medieval and 19th century writings

"Only." This is impressive!