A euro cylinder is measured from the screw hole outwards and inwards, not over its whole length. Calling a 30/40 cylinder a 70 is how you order one that does not fit or that sticks out too far, and a cylinder that sticks out is the one that gets snapped. That is why there are two boxes here and not one.
This is the list that matters. A building gets five cylinders and sixteen keys, and three years later nobody knows who still has one. The moment somebody leaves or something goes missing, that is the only question, and a list nobody kept is worth nothing. This sheet has names on it: it stays in your own browser and goes nowhere, but a printed key register does not belong on the counter.