Marcus Bonna Dolce Musical Instruments Custom Euphonium Semi-Hard Case

This is a Marcus Bonna semi-hard case for euphonium. This is a special order model from Dolce Gakki (with added shoulder strap and some leather parts), so its specifications differ from the catalog model of that time.
* Please note that this is not a current model, so the detailed specifications are different.
It is a 3-way type: hand-carry, backpack, and shoulder strap. (The catalog model at the time did not come with a shoulder strap.)

Please read the following description.
Purchased nearly 15 years ago, it was used about 2-3 times a month for nearly 2 years, only for transportation by car. After that, it was stored in a closet at home as I used another case. I believe there are no noticeable stains or dirt on the exterior or interior.
There is some tarnishing on the metal parts of the backpack section, the leather reinforcement, and the zipper hardware, possibly due to humidity.
It was used as a backpack only a few times (I don't think it was even 4-5 times). The case weighs about 5 kg, so it is quite heavy compared to a soft case.
Also, there is a note regarding its use with the shoulder strap. In the current model, the shoulder strap hardware is fixed to the top of the case, but in this model, it is sewn into the side. When I used it with the shoulder strap at the time of purchase, I felt that excessive tension was applied to the case, so before it could be damaged, I took it to a bag workshop and had it reinforced on the back of the fabric with canvas, reinforced stitching, and added rivets (photos 11-14). However, I thought the angle itself might be problematic, so I only used it for hand-carrying thereafter.
Accessories include a mouthpiece case and two sets of backpack straps (one is an inexpensive commercially available one, but I think it's better than the genuine one lol).
A new Marcus Bonna semi-hard case is quite expensive. This is a product from nearly 15 years ago, but I believe it is still a usable case.
Thank you for your consideration.

It will be shipped in recycled cardboard.