The early A-100 barrel shaped lock cylinders interchange with D-100/200/300/400 or other barrel shaped lock cylinders of that body style. These may interchange all the way into the early 90's trucks, not sure, looks very similar.

Even if they're slightly different it's usually only a matter of the flat steel shaft [length & width] that carries motion from lock cylinder to latch mechanism, so you can easily adapt. Most any similar lock cylinder that fits the door hole could probably be adapted with little fuss.

You can have your cylinders rebuilt at least by having new brass pins installed to replace worn ones and matching existing keys.

Most passenger side locks got a whole bunch less use so if you hit the yards you can get better cylinders off passenger side & have them re-pinned to fit your keys.

Nobody I know of does repops right now, not likely in the future.