^ sorry, does this mean I'll never be able to use mine as a phone in the USA?
Or possibly not possible in Europe, too?

It says Verizon on the front and XT894 under the battery cover.

I have never tried using it as a phone when I got it, and now I cannot boot into Android anymore.

edit:
@OP: https://www.ebay.com/sch/i.html?_nkw...+xt894&_sop=15
As you can see, there are a few, and they're cheap. But almost all of them from the USA. Import taxes & shipping are roughly as much as the buying price. Ebay counts the correct end price for you, or at least it did in my case.