There must be some since Mike has several 4mm Mod1 pinions with tooth counts ranging from 10T to 20T in the store. Actually, according to the
BK-Electronics site, the LMT 1950 has a 4mm shaft.
By the way, I wasn't trying to be mean or anything. I thought you were poking fun at the terminology when you said "that its a 4mm axle? Does that mean its a 4mm shaft? oops...". I apologize for the misunderstanding.
EDIT: And I'm not one of the forum leaders, regardless of post count...