In this hobby, you never know what will spark a quest. In this case, a 1956 advertisement for the Tissot Futura ("Wear it forever without winding") started the chase:
The name "futura" never appears on the dial, which just added to the challenge of identifying the right model. It took me a while to find a wearable example, but the balance spring was shot and crown was missing, so a second parts watch had to be tracked down. It's a good thing the watch can be worn forever, because that "thinner sleeker automatic with the invisible crown" is a challenge to wind. Even so, I have found I'm quite fond of the no-crown look.
The white dial version seen in the ad is easier to find, but the black dial version seems to be scarce: