I did contact Rain-Bird before I started this post. All they could tell me was that they "think" it looks like an old PEB valve and that I would have to rip out the entire thing and replace it.
It is a Rain-Bird valve - it's stamped on it.
Greetings! I am trying to identify the model of the value in the attached photo. Even more importantly I am trying to find its suitable replacement part. I need to replace this value and I don't want to rip out the entire value assembly - I just want to replace to top portion of the valve.