So it´s goint to be a projet for another time
= NEVER, I bet!
If you don't know or find out the controller type you won't be able to find a library.
In that case you have to write the controller yourself - which is not easy at all and will take more time with a vague or very disappointing result.
Go with an Arduino compatible/supported standard LCD display and you will be fine.#
Even those guys could be a pain i.t.a. if you don't pay attention to a proper soldering, right constructor, right library etc.
Save your precious time for other things than dealing with unknown devices. Sorry, but I have to join @julyjim in not encouraging you.