It’s fairly common for vintage lenses to have their quirks.
Aesthetic quirks are usually embraced, it’s often why a particular lens is a selection in the first place, but mechanical quirks can be a whole different beast.
Some older lens sets require little modification to get up to spec – conforming all front diameters to the same size for ease, or using a thicker focus gear because one of the lenses telescopes a little.
But there are some popular lenses out there that are particularly tricky. Take the Lomo Round Fronts, for example, they telescope (substantially) as you focus and the front of the lenses rotates.