Some prototype based languages use delegation instead of inheritance, so people assume that is the case for Self as well. The difference is subtle. But as you pointed out and Mario Wolczko said: "Self is like Smalltalk, only more so". There were also languages with neither inheritance nor delegation but that still included some scheme for sharing.

Prototype based inheritance is another matter.

Original VB was definitely OOP, especially since VB 4, when VBX was replaced by COM.