Series 3 Locks on door tops - top or bottom?

I've got an early 1972 station wagon (A suffix) that needs the door tops replacing. The door tops in there at the moment have the S2 style window lock at the top and the square lower window locks are blanked off.

I'm trying to figure out what would have been there originally. I spotted that the parts catalogue shows the top lock as optional. Were the early ones fitted with the top lock and not the bottom one perhaps?

my 1974 station wagon has them top and bottom, don't know if they are original though- I suspect not.

I've got both 83 model.

If its a S3 it should have the square type push the button in to allow the catch to slid up and down but it doesn't really matter which type is fitted really, its probably a good idea to have both types fitted gives a bit more security, think I mite go this way myself

It's quite straightforward to fit both and the parts are cheap.