Some thoughts: Try finding a book on Greco-Buddhism. You won't. You will find books on Gandharan Buddhism, which is the actual name for a vibrant and dynamic form of Buddhism which led to a lot of what's in Mahayana.
How wikipedia lets that slide, when there's a vigorous debate over waht Louis XVI ate for breakfast before his execution, I dunno.
Anyway, the problem is that your window is prettty narrow; Gandharan Buddhism didn't really flower til the 1st century CE, 2nd century CE. Before that, you get an aniconic religion based on the Buddha's past lives. It's still an option, but, hrmm.