J76 Park Brake Park Shaft

[dagnabbitt]

So I am trying to get my 1968 C20 on the road - build thread coming soon I hope - and it's getting interesting.

The truck has numerous odd features for a vehicle purchased by some Canadian farmer 50 years ago, but the one that is stumping me is the J76 code in the thread title. Very little mention of this code in the forum except that it is considered quite rare and most people seem sure that it was only offered on C30s.

I understand the basic concept of a prop shaft ebrake, but I don't really know what I am working with here. It seems like it is missing some pieces... for example I have no idea what it is supposed to look like, much less how to engage it: is there a handle or a lever somewhere?

If I am unable to repair or restore it, can I just add a regular old drum e-brake?

Does anyone have any knowledge of this component, pictures, anything at all would be appreciated.