Mate, that is nice. Be very sure you use a quality screwdriver that is the perfect fit and don’t force it. Nothing worse than shearing the heads off those back case screws.
Yikes! I hadn't considered shearing the heads off ! I got a set of Bergeon screwdrivers that seem to be pretty good...any other advice re those screws?
Interesting. I’ve never seen an Astronaut with a calendar! So it can’t be a model 214. Yet I’ve never seen this style Astronaut with a model 218 (calendar) movement. That, plus your watch appears to not have the Astronaut fourth (24-hour) hand! Was this watch made to loosely resemble an Astronaut? Vintage? More info please.