In majuscule forms (i.e., all upper case) V was the normal shape for u/v while in minuscule forms (i.e., all lower case), u was the normal shape. This is why you’ll see V in engravings rather than U. Albrecht Dürer‘s Of the Just Shaping of Letters which shows only upper-case forms provides a V shape but not a U shape. His textura, at the end of the book, has a single letter in the upper-case, but both ü and v in the lowercase with a distinct base character beneath the umlaut for ü.