Good question....I think it depends on what vehicle it came on. IIRC, some of the spark plug brackets got moved around between some of the car models and also truck/van models. You'll probably need to find someone with a known virgin engine to compare yours to.
The original valve covers in my 1965 Dart 273 GT have a metal PCV valve which slides over a stovepipe stub on the valve covers. Same in my 1965 Chrysler 383. The PCV sits in a metal can which slides over the stovepipe, secured with a nut on its threaded body.