Door locks, trunk locks, ignition lock cylinders....
The 4 door is a 1969 model and I understand that the ignition switch and lock cylinder are a one year only setup?
The ignition switch is one year only- but the rekeying/recoding procedure is the same.
While it may not apply to your particular situation, for others who may be reading this there are some differences over the years.
Early door locks ('65 and earlier?) were a different diameter than later door locks. While this doesn't affect rekeying, it means an early lock will not work in a later door- the hole is too big. Likewise, a late door lock will not fit in an early door unless you cut the hole larger. An electrician's Greenlee hole cutter works well for this, although hand filing or a Dremel will also work. All repros that I've seen have been the later large diameter locks; so if you're dealing with an early door lock, then rekeying/recoding is your only option.
Pairing of the keys also vary according to the years- '66 (maybe'67? or thereabouts) and earlier had door keys that matched the trunk style key. After that the door keys matched the ignition.
IIRC, there was a slight difference in years for the changeover in trucks vs cars, but they did follow suit (yes, I know trucks didn't have "trunk locks", but they had that style key which also fit the glove box lock if so equipped).
Just a little more info to pass along.
you can do the poor mans hack, get your chosen ignition lock and key. get a selection of door look barrels. fit the key in each to identify the pair with the least number of pins or sliders sticking out with the key inserted. hopefully just one or 2 out of the full complement of 5 or 6...
File down flat with the barrel any that stick out and check that the barrel with the key inserted turns in the lock body, and won't turn in the lock body when the key is removed...
With all due respect, that isn't how the cylinders work- at least the ones supplied for use in the U.S.
The pins NEVER protrude from the cylinder barrel so there is nothing to gauge how much to file off. The springs may stick out if they haven't been distorted, but the paired pins seat against each other deep in the barrel with the spring on top, retained by the press-on cap.