Jeez, I hope a previous owner didn't slot my upper over center spring mount to make extra adjustment ... could easily weld it up and redrill if necessary. Actually I have the machinery here to make new ones if needed. But I'm kind of looking at a pile of parts so memory might not serve accurately
I recently bought a small 12vdc vacuum pump ... when the time comes I'm going to hook the whole thing up, right down to the headlight switch and vacuum storage canister and test everything.
I think the bushing in that rod support is the first thing to go in most systems ... I don't think I've ever seen one intact on a parts bumper.