This one I bought some months ago in an auction.

From the research I made on the web and in another forum (I hadn't found this one yet) it is most likely what is on the title.
Basically a Eb fanfare with an added valve section.

What I can't still figure out is if it is something someone asked the brand to do, or if the brand itself experimented and did some examples of this horn.

It can only be a Frankenhorn. That tubing layout is not very practical or functional. The "UFO" tube decoration that is a typical decoration for natural trumpets under the finger pads cant be very comfortable.
Further, the way the first valve loop's one tube attachs to the valve is far from professional.
Not removing the solder marks from prior use isn't professional either, so I doubt an instrument maker would introduce such a prototype to anybody.

My "verdict" is that this used to be a natural trumpet that maybe was re-tuned into another key and was equipped with a valve section, which again was eqquipped with valve loops of which at least some were not original to that valve section. Also notice that the loops point away from the keys, where they are normally found under the keys on normal rotary valve instruments with clockspring mechanism.

It appears to me that you may also have equal lengths of tubing on the first and third valves.  Is one of those an ascending valve (I'd guess the 3rd)?