“James Dean” and “Marilyn” haven’t missed a thing that has happened on their corner of Dorchester Avenue for the last 34 years, but passersby would struggle to get them to say anything about what they’ve seen. That’s because they can’t talk; in fact, they’re not even alive. The two 1950s-era statues in front of the Boston Glass & Boarding Service at 1068 Dorchester Ave. are as