Smalltalk started in '71 and was used for research purposes in '72. Smalltalk '80 was the definitive version for most. This means that Smalltalk slightly predates C. By comparison, C++ didn't start until 1983.

You wrote "your ability to write Java source in any text editor at all was, all by itself, a new method of doing Object-Oriented Programming".

Simula, considered the first OO language, is text based in the same way that Java is, and not image based like Smalltalk. Since Smalltalk is inspired by Simula, I do not believe one can say using any text editor is a new method of doing OO programming.