Thank you for posting the update, you are now the forum resident expert on Rochester type M carburetors, congratulations!
The Rochester single barrel carbs, whether the type B or the type M (monojet) get a lot of negative press (most of it deserved), but occasionally, like this time, they are not guilty.
The import from China fuel pumps, fuel regulators, and carburetors all have one redeeming feature. They are quite useful if one has a strong right arm, and a rabbit problem in one's garden. The imported from China carburetor rebuilding kits are too light to do any harm to the rabbit. Maybe someone can find another "repurpose" for the carburetor rebuilding kits.
There is a company in the Boston area, Then and Now Automotive, that manufactures fuel pump rebuilding kits. I am pretty sure the kit components are made in the U.S.A. They also have reproduced many older fuel pumps. I do not know if they produce a pump for the stovebolt.
Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify
If you truly believe "one size fits all" try walking a mile in your spouse's shoes!