Why in Florida, the lightning capital, are lightning rods so seldom used. I've seen many in the North.?
I believe you are talking about rim cylinder locks as opposed to euro profile, if this is the case then the sections that you are talking about are designed to be smaller than the minimum increment that could determine whether the bar bites into the latch handle on the other side. In other words do it one section at a time, or measure it against the old one. The sections should snap along the grooves using a pair of pliers.
I have 3 extinguishers, living room, kitchen and bedroom, and smoke alarms in each room. Since there are no children here, me and my wife both know which way to go in case of a fire.