Here's some photos
It's a push on type.
The "push on" design/style refers to the bottom plate of the breather cap as compared to the twist style used later
Yes that's the design that is often seen on small blocks with closed emissions and as mentioned in the thread listed above.
What Bob was referring to (also covered in the other thread) is the adapter that attaches to the valve cover so that that style of cap (push on base) can be used.
Push on neck required for that style of breather caps (example from a 67 small 289)
Adapter visible on a 67 390 application
Without the adapter you can use (some owners do) a later twist on breather cap like this creative owner did
Have only seen that decal used on restored 67. Just my observations
