DMCA doesn't apply outside of USA but the core copyright conditions are the same pretty much everywhere, with the only one in Europe who isn't a full member of the treaties being Kosovo due to differing opinions about recognizing it as an independent state.
"Decades old" is far from being sufficient to become unburdened by copyright. Works with joint authorship (as movies almost universally are) generally become public domain upon 70 years of death of its last remaining author - e.g. for movies you have to wait until the principal director, the author of the screenplay, the author of the dialogue and the composer of music all die, and then 70 years after that, so it's wouldn't be even surprising to have even the very oldest surviving movie of some country be still under copyright if one of them survived WW2.
"Decades old" is far from being sufficient to become unburdened by copyright. Works with joint authorship (as movies almost universally are) generally become public domain upon 70 years of death of its last remaining author - e.g. for movies you have to wait until the principal director, the author of the screenplay, the author of the dialogue and the composer of music all die, and then 70 years after that, so it's wouldn't be even surprising to have even the very oldest surviving movie of some country be still under copyright if one of them survived WW2.