I'd call that a C-Case rather than square, it curves around towards the lugs. It's a nice retro design imo. Front on image for a better view of the case:
It is not so much the watch being a chronograph, it is the fact it is in a square case, which, generally, I don't like the way a square case sits on my wrist. That being said, it doesn't mean I don't find square cases chronographs unappealing, take for example the Tag Heuer Monaco. I have round, rectangular, tonneau, c-shaped, octagonal, and cushioned, but no square.
Lovely piece Daniel, same case as my Iaxa with valjoux 7733. Both of our pieces have dials probably made by the same manufacturer as well, Singer. Although yours is even more likely to made by them given the squared subdial markers.
It's hip to be square. Citizen Chronograph Automatic Reference 67-9071 with caliber 8110A aka Monaco.
I really like the cushion case chronos and the full blown square. The chunky one below is mine. I don't have a TV El Primero but it is an under appreciated beauty.
Wow, I didn't know that was a thing. First time I've seen one, and I thought "that looks a lot like a Seiko 7016 'Monaco' ". It is a lot like the Seiko 7016 Monaco - as well as rebranding the Seiko movement, there are some reports that the Mantagraph used the same case, but I think that's not so - the Seiko 7016-5000, 5010 and 5020 all had different-looking (though very similar) cases to the Mantagraph. Every day, as they say, is in fact a skoolday. The Other Seiko Vintage Chronograph 7016 [by guest contributor – Mr. Chow] | musingsofawatchaddict (wordpress.com)
I think the late 90s Tag Heuer reissue of the Monaco offer good value these days. I picked up one towards the end of last year (but gifted it) and picked up another last week. Paid less than 1500 eur for each. I very much like the Heuer branding on the dial, and at 38mm it's versatile. I think there is little in that price range that offers a similar package. The Zenith above and the speedmaster TV dial are on my list, but for the moment to this is my only square dial chrono.