I'm personally convinced that Astronaut M1 18kt was made long after 1962 ... probably after 1964 but with the date M1 on the caseback. An advertising “move” or maybe just a frankewatch ...
also ... the only "AD" I found on an 18Kt gold Accutron astronaut is from 1964. I doubt Bulova didn't advertise an 18Kt astronaut accutron in 1961 ... if it really existed.
One thing I have learned is not to argue with someone with alternate opinions. Whatever you think is fine. Just keep in mind two Things.
1. The 18Kt Gold Watch case which is an Astronaut case is dated 1961. You can't change that fact!
2. Also the Platinum Accutron Model 703 (pictured below) is also dated 1961.(Not related to any astronaut but a rare specialty example that was not promoted and absent from many Bulova listings.
3. Neither showed up on Bulovas Price list in 1961 even though they were both
dated 1961. Both were on the price list in 1964. So just because they weren't on a 'list' doesn't mean they didn't exist!!!!!!!!!
And if you notice, the two examples on this post are 'specialty' limited run extremely expensive early year Accutrons that had nothing to do with all the mass producing of the Stainless Steel Astronauts seen in 1962 and later that you are trying to compare it to. I wouldn't try to associate these rare 18kt gold Astronauts with the mass-produced Stainless Steel versions. Two different animals. But, how it all fell into place in a timeline will probably stay somewhat of a mystery.