Hello Uwe, saw your thread in Public, and being a masochist . . .
I am not that familiar with the Laco brand, and regard it as basically quite utilitarian. Having taken a look at the current line up, it is mostly very traditional, with many varieties of the perenial pilot's watch, and several fairly straight forward Navy watches. The only ones which are really of any interest from a design point of view are the more modern Navy watches like the Navy 44 Black. One might be able to spot that such a watch was a Laco from a distance. With the pilots you can forget it, they just look like every other pilot you can get.
A limited edition can and should be much more than a slight variation on a current model. If you work on it enough and get sufficient input you can arrive at something very distinctive and appealing. It should be something which Laco would likely never introduce as a variation in the future, because if so there would be little point in putting in the effort.
So, identify what Laco already does well, and move away from that. Well, more precisely "grow" away from it in an irregular direction. This way the project generates its own unique flavour.
The movement and case restrictions limit the project quite a bit from a features point of view. No GMT, chorno, bezels, alarms, day dates etc etc. Therefore, the juiciest part will be the theme and the face design.
We are talking in this thread about the theme. So, what themes does Laco already use? Obviously it is entirely military, with Pilot, Navy and Squad sub-brands. I suggest the SE moves away from the military theme, but maintains some kind of root connection to the core brand. The obvious and rather cliched horological themes peripheral to the military areas are the professional ones like diver, commercial pilot, explorer and so on. I would rather avoid these because they are so derrivative and have been done to death.
How about moving in a slightly different direction towards celebrating some pioneering engineering achivement, which might in itself not be directly linked to military themes, but can trace some kind of connection. For example, a watch based on early ballooing, early air-ships, internal combustion engines, steam engines, racing cars, racing planes etc etc.
Air ships intreague me, and would have a German connection. Although, one can buy Zeppelin watches already I believe, so the SE would have to steer clear of that. Germany can also claim to have invented the internal combustion engine and the first car.
German produced the first functional helicopter, the FW 61. Focke-Wulf Fw 61 - Wikipedia, the free encyclopedia
How about a watch design inspired by that?