I have a number of original interior passage knobs in my late 1940s house that would greatly benefit from tubular latch replacements. They have friction in them and often stick with the latch retracted into the door. No amount of cleaning or graphite seems to help.
I'm looking to purchase replacements, but am stuck on the first step: trying to determine what the backset is. Seems the usual sizes are 2 3/8" and 2 3/4", neither which seem close to the measurement from the front plate to the middle of the door knob hub. In reality, 2 17/32" seems to be the measurement.
Can anyone provide some clarity?