its origin..you already know....genuine Satsuma comes from the Satsuma region of Japan....but the world is awash with fakes made in China...
NO genuine Satsuma ware was made in China.
NO Japanese Satsuma made before 1900 will have any markings in English.
If your eBay seller is offering a "Meiji Period" Satsuma item and it bears any of the markings illustrated above, your seller is either ignorant or deceptive or both. If your seller represents any item as Japanese Satsuma of any age and it bears any of the markings illustrated above, your seller is either ignorant or deceptive or both. Buyer Beware! An honest seller will correct his listing when he is informed of his error. A dishonest one will try to perpetuate his deception.
Currently there is a dishonest eBay seller in Texas listing cheap new Chinese items misrepresented as being "Meiji period Japanese Satsuma with 24KT Gold" or other such nonsense, that his "army grandfather" had "traded for" various items such as German helmets, beer steins, etc. as "war booty" in WWII. You can find these listings, open and closed, by doing a word search on eBay using those terms