(This doesn't answer that person's question, I didn't want to disrupt that inquiry, so here's a separate thread as a sidebar.)
I understand wanting quality components for our frankentubas, particularly when some of us are quite meticulous, in regards to our builds.
The thing is that some (SOME) Chinese parts - these days - are every bit as good as European-made parts.
The following is not a specific brag on JP. (Realize that JP doesn't own a factory, but has contracted one factory to build their super-nice things and a couple others to build their regular-nice things.)
... the pistons and casings on the JP sousaphone, the JP C tuba (though I'm not personally fond of the C model they copied, yet others are really fond of that style), the JP euphoniums ... These components are as good as any.
I understand being skeptical and that seeing is believing, but I've seen, and I believe.
The same thing goes for the rotary valve instruments sold by JP (again I'm not so much talking about JP as the factory that makes their things). So far, we haven't been able to get the factory to make the stop arms fit nice and snugly on the rotor stems (I suspect that sort of fit requires laser cutting those holes), but everything else about the rotors and casings - as well as inside outside slide tube fit and pairs of slide tubes' alignment - is as well-made as I would want on any of my personal instruments. Truth be told (some of us remember), Miraphone was this way for a few years when they were into the DVS linkage era, but they've addressed that long ago themselves.
Again, this isn't really a JP brag, but I'm just pointing out that there are some really superb band instrument components built in mainland China.
Now I'm stepping over into the political realm, but NOT for the sake of simply being political, but to discuss how we feel (emotionally speaking) about from whom we purchase things:
I don't personally view ANY country as being a so-called "ally" of the United States. I believe the ONLY reason that other countries' rulers show their smiley faces to the USA is because the USA gives them things or gives them money. In regards to these views of mine, I exclude NO (so called) allies from these views. (Think through some of the United States "best" so-called "allies". The US has been at war with most of them.)
Understand that I'm not against any other countries and I don't blame them for accepting our free stuff and our free money, but I don't view them as genuine friends of the United States - none of them.
That said, if some country has some privately-owned or state-owned factory that makes some really excellent components that work on fill-in-the-blank as good as anyone's - and that stuff isn't made anywhere in the United States - I'm going to buy it from the place that makes it the best (and if the cheapest happens to be the best, or equal to what is believed to be the best, I'll be going there).
Going even further, sometimes we look at a component or a tool and decide that we only need one that works okay for a short time, and - if we end up getting good service out of that component or tool for a long time - we consider that a bonus. That's why places like Harbor Freight exist (as well as some of the lower-end Chinese instrument factories which - even those - are starting to step up build quality of their what-have-yous a bit). That said, Harbor Freight quality is stepping up as well, as some of us have noticed.
The fifth rotor on my compact 4/4 Holton B flat build is a Jinbao rotor off of one of those really early crappy/unplayable (imo) 6 valve Miraphone copy F tubas. When putting the Holton instrument together, I was getting ready to order a 19mm bore Meinlschmidt rotor assembly, but I looked through those six rotors, rejected most of them, but found one or two that were actually made pretty well, and I picked the best of those two. That rotor assembly has been trouble-free.
We can generalize about brands and countries and whatever, but really good stuff can come out of places with poor reputations and really crappy stuff can come out of places with really good reputations. (Who remembers the era when the German "big valve" piston casings had issues with roughly-cut valve guide tracks, and repair people were having to go back and carefully file and burnish those tracks so that the valves would go up and down without sticking - as just one example of the latter?)
I caught one person here in a rhetorical discussion whereby I got them to admit that they were fine with Japanese Asian parts and instruments, but not Chinese Asian parts and instruments... I wonder how surprised some people would be were they to discover what percentage of Japanese instrument parts (and then quite a few cases entire instruments with Japanese brand names) are made in China... and of course we all know that the French company that owns the big German factory is having a whole bunch of stuff made in China.
Sadly, I'm not particularly impressed with what remains of American band instrument manufacturing, which is now down to a drizzle.
(A friend of mine owns a pretty large band instrument business and website that advertises nationally. At least for a while, they were picking up gobs of professional grade American instruments from the factory - yet with no cases, because they weren't passing final inspection, and the factory didn't want to waste the fancy cases - that they were having made - on those instruments.) I understand that some people aren't going to agree with a lot of what I said and so what? I'm sure that - if they respond - I likely won't agree with some of the things with which they will respond.
I am seeing some mom-and-,pop American manufacturing suddenly occurring - now that there's been a shutdown (which I personally expected).of one of the last of the big American factories. This small shop activity is interesting, and I'm watching.