It’s just an Omega customised 7750 variant really so should be fairly straight forward. Much less grief than a Speedy Reduced for instance.
Because the 7750 and derivatives including the triple date are integrated once piece designs. They too have drawbacks, they only wind in one direction and are rather thick for instance, but can be serviced by pretty much any competent watchmaker (unless Omega specific parts like the rotor need replacing but even then other parts may fit. The 1140 and 3220 are in fact 2 piece designs using a regular 2892-A2 three hand calibre you can see when you open the back with a Dubois-Dupraz chrono module on the dial side you can't. Your options for servicing these properly are much more limited as parts for the DD module are not available on the open market. At all. To anyone. Some watchmakers will service just the 2892 and ignore the DD, some, a minority will actually disassemble and lube the DD but god help them if something pings or needs replacing. Omega just swap out the whole movement for another and send the awkward bits to DD on an exchange basis. In short if you are happy to pay Omega the £700 or whatever for a chrono service they are the same but if you want to go cheaper, the 7750 is easier on the servicing score.
Some info:
https://www.watch-wiki.net/doku.php?id=omega_1140
Because the 7750 and derivatives including the triple date are integrated once piece designs. They too have drawbacks, they only wind in one direction and are rather thick for instance, but can be serviced by pretty much any competent watchmaker (unless Omega specific parts like the rotor need replacing but even then other parts may fit. The 1140 and 3220 are in fact 2 piece designs using a regular 2890 and 2892-A2 three hand calibre you can see when you open the back with a Dubois-Dupraz chrono module on the dial side you can't. Your options for servicing these properly are much more limited as parts for the DD module are not available on the open market. At all. To anyone. Some watchmakers will service just the 2892 and ignore the DD, some, a minority will actually disassemble and lube the DD but god help them if something pings or needs replacing. Omega just swap out the whole movement for another and send the awkward bits to DD on an exchange basis. In short if you are happy to pay Omega the £700 or whatever for a chrono service they are the same but if you want to go cheaper, the 7750 is easier on the servicing score.
Some info:
https://www.watch-wiki.net/doku.php?id=omega_1140
