This website came up on another forum:
http://www.minkow.com.cn/Table-tennis-seriesQuite interesting. Apparently they'll sell you XSF seamless balls wholesale. They have one-star bulk packs, too. But the other offerings are just as interesting. Such as balls for the sight-impaired (Nittaku makes some, too), glow-in-the-dark balls, balls for bingo (some with RFID chips!), 50/44/40mm balls in sets of six (like Tibhar sells - betcha they're the same ones, too) and 38mm balls, which I know some people were looking for.
They've got Shield and Double Circle balls, too - you still find Shield balls in Chinese bookstores around here, I used a lot of these (in the 38mm version) in my youth.
Also:
http://www.minkow.com.cn/Aboutus-ShanghaiMinkowCoLtdYes, they do make balls. And they OEM for Tibhar, Stiga, Donic, Joola AND DHS!!! I'll bet I know where DHS balls come from. Note they're in Shanghai - who else is in Shanghai????
Look at all that celluloid waiting to go up in flames...
Iskandar