Interesting, I would not have guessed Chinese based on the size and what I see in the pics. Although there are some similarities to the colors of single pontil "confetti" marbles that are rumored to have come from China. Maybe I'd have to see more 2-pontil Chinese marbles to compare it to.
One of the pontils looks a bit odd, could be an "inny" rather than an "outty" but not unheard of. Is there any grinding or faceting? (might not have been necessary if it didn't stick out)
Really cool marble and discussion, but to me it really looks like it could have come out of Germany, just like some of the other hand mades that were produced there. Definitely unusual colors and construction but I don't see anything that would rule Germany out. My opinion and if I'm wrong well maybe I'll learn something new:)