Chris - before you dive in and start taking apart the Landeron, make sure you understand which screws are actually screws, and which screws are really eccentrics. Don't even put a screw driver in any slot to turn anything until you know what it's function is, because you don't want to mess up the eccentrics. Putting them back might be a bit more than you bargained for at this point.
Now they still may need adjusting, but as I've said before, do the service and assume everything is okay until you confirm it's not, then start adjusting. Do you have any reference material for adjusting chronographs? If so, read it over carefully before proceeding.
Once you get it all set up and running well, if you want to be challenged you can send it to me and I will mess them all up for you, and you can practice putting them back - my instructor used to do that while we were having lunch!
😀
Cheers, Al