The Chinese Tecumseh rebuild kits fit the Chinese aftermarket Tecumseh carburettors
The Chinese manufacturers do not "copy" anything they manufacture to order, often to the sample provided by the US businessman .
If dealers would tow the line and order the needles in wholesale quantities of say 20 to 50 at a time then they would just sell you the jet for a reasonable price.
However only fools like Star & myself carry a large inventory
I have just taken delivery of 50 Nikki rebuild kits , 10 intek head gaskets ,10 Wabro twin rebuild kits etc etc etc $ 2,000 all up
The local dealers do not stock any of these parts ( so I found out the hard way ) and just order them in as required ( minimum inventory thus minimum capital ).
Because they are run by accountants not techs
When DC spares were happening I used to put a $ 1000 order on them for cube carb & victa carb parts every year .
B & S made the mistake of having no minimum order value and free overnight delivery so naturally it got abused
I'm sure this is all true in some instances but not always. Generalizations always tend to end up that way.
I was kind of making a joke as to the old days for Japan did the same thing like taking a us-made Zippo lighter and then copying it and then selling their cheap copy at a third of the price. China started doing that decades later but it just became more widespread.
I'm sure that in today's age if you send somebody the cad file for something they can give you a price on making it.
Then it gets into all those logistics that you mentioned but that's not really of concern to me and nor should it be to you or anyone else.
I don't think we can change the way the world's working now and we're left to just gripe about it and then to be proactive and once we find parts that work for us to buy large quantities so we will always have them like you just did.
I also do the same. I buy little gaskets sometimes 50 and 100 at a time but almost always 10 to 30 at a time. I bought a dozen head gaskets the last time I bought them.
So whoever's fault it is, I don't know, but they need to get with the program because those Chinese Tecumseh carb gaskets aren't even close to the original.
I could measure with my $6 set of harbor freight dial calipers that aren't even digital because they're real dial calipers and could give a better dimension than they ended up with.
Another weird thing that's kind of frustrating is who decides what the Chinese companies start Mass producing and export and whatever so it becomes available to us??
Just like a few years ago when there were no Kawasaki small push mower engine carburetors available but Kawasaki brands.
Then all of a sudden they pop on eBay and Amazon for $36.
No, they're not nearly as good as the Kawasaki carb but I have 100% success rate so far with installing them and pulling the rope usually only one time and they're firing right up and running perfectly.
For 36 versus 136 plus I'll gladly take those all day long.
But my point is for a number of years I wanted them but they weren't available.
I understand mostly it goes by once there becomes a big demand for things.
For instance the 31xxxx head gaskets were only available from Briggs for a long time and then all of a sudden here they were on eBay not just one but two and other gaskets with it for super cheap compared to just the one Briggs gasket.
Same way with the camshafts but when the new brakes came out the new plastic camshaft that little blue one with the little metal top hats on it because they were just mostly stupid but they did realize that they couldn't just stick the plastic end into the engine cases but it still a piece of junk...those weren't available from anywhere but Briggs and maybe the last I checked a couple months ago it was still this way.
But we all know that soon enough there will be aftermarket replacements. Possibly by oregon, stands or rotary which are the big three that make fairly quality stuff but they will also be no name ones just like those camshafts all over eBay and Amazon flooding the market for a third the price.
Now, I gave up on those camshafts because even though the factory ones are pretty bad, the aftermarkets were even worse and after having one only last 4 months and about 8 mows I can no longer spend even the small little $37 to buy one because the time involved to fix.
Now with the plastic Briggs camshaft and the smaller ones, the factory one is such junk that a Chinese built generic could actually be an improvement!
But my point was how do we get a direct line to these people to build what we want? Actually I guess it's the other way around like you mentioned at first you have to have some us companies or businessmen contact them and contract them to build it for you.
That's the big mess and only works when they know they have a market to sell lots of them from the mass production required to buy them anyways. Can we say Alibaba? Yes, I would like to order 10,000 units of this part that I need one of.