This is a rim lock on a swinging "carriage style" garage door from 1925. The lock is terrible, very hard to adjust, and to keep adjusted as seasonal variations occur in the spacing. The lock is keyed on the outside.
What type of lock would be better?
Best Answer
The lock is a standard household door lock, not really designed for doors that slop around as much as garage or barn doors do. You'd have to do a bit of jury-rigging, since they are virtually all designed for modern-style roll-up garage doors, but a garage door style lock will have considerably more slop and adjustability. You'd probably have to mount either an actual section of garage-door track, or simply something else with a slot to accept the tongue/bolt to use most "garage-door" hardware.
Here is one I found looking for "gate" locks, described as a "long throw rimlock" (key cylinder on the other side, this is the inside view) that would not appear to require jury-rigging. Note that there is considerable room for the parts to move up and down or side to side while still locking.