Many international versions cut explicit scenes to avoid an X rating. The authentic Brass cut should include:
Arrow released a stunning Caligula box set (though it excludes Brass’s explicit inserts). For the true Brass fan, their editions of The Voyeur and Hotel Paradiso are the gold standard. tinto brass collection link
If you find a "complete collection link" that misses these titles, it's incomplete: Many international versions cut explicit scenes to avoid