OK: update!
I have given this bike back to the shop (at a loss, of course!) ..and that was not in order to have another look at the secretaries!
Why?
1- Because the sound level was ridiculous once over 5,500 revs, while the power was ridiculous below! One could say: "just change the exhaust", but I had no intention to spend thousands in an in-depth comparison on motorcycle exhausts! I had been riding that little bike for a 1,000 km, and as I could feel the engine getting run-in and more free, I could appreciate the correct power (for a 125) it was delivering at 6,000 revs, but below: zero! My also 125cc single cylinder push-rod Hoajiang, which I happily still had, gives a good lot more starting at 4,000....and silently!
2- Because horribly uncomfortable on a long ride! Oh, the road-holding - and breaking - was superb with this rigid frame, but also nearly rigid seat! Front suspension is also pretty stiff, and just destroys your wrists with this low hand-bar!
3- Because.... my wife hated it! Used to the wide, comfy seat with a comforting pad behind her back of the cruiser style Hoajiang, this screaming little thing was just a no-no!
4- and last because it is: a cop magnet!!! Without doing any offense, I got stopped three times in 1,000 km. by cops suspecting some illegal transformation, or just that I was over-speeding! Can't really blame them: you should have heard that thing: most aggressive sound I ever heard from a bike!!!

Well: I am a bit sad, actually! Was happy - of course! - to have a new bike, modern, with a twin cyl. engine (although a disappointing one), and looking forward to some sporty rides, but have to look for something more "civil". Will let you know.

Oh, by the way: yes, it was Chinese!