Does anyone know exactly which Rockwell company or division of the Rockwell conglomerate was contracted with Gottlieb?

I suspect this division may have been tied somehow into industrial automation. The leading industrial automation company in the late 70's and 80's was Allen-Bradley and wasn't purchased by Rockwell until 1985. Westinghouse, GE, Reliance, Rockwell, Allen-Bradley, etc. all had divisions in the factory and industrial automation space, and they each had their quirks about how things were done.

Based on my own personal experiences with industrial automation systems, which are far more complex than a pinball machine, I would be curious to know.

Black Hole (The Black Hole)

Do you know the year of this photo? Northlake, IL or Chicago?

I am not sure what this means. What exactly didn't make much sense to the Gottlieb repairmen of the 80's?

I think the "bullet-proofing" of System 80 machines is done today because they're 40+ years old and people are willing to spend time and money. Back then in the arcade, it's was about just keeping the game running and making money as quickly as possible for the least amount of money. Apples and oranges.

It's not like we have some new profound understanding about how they work that didn't exist in the 1980's.

I'm not disputing the existence of these issues/flaws in the machines' design/construction. I am simply asking you for clarification about your specific comment...

"They all make sense now - back then not so much" ... This is baffling. Do you really believe that today we have some profound new understanding about how they work that didn't exist in the 1980's?

The engineers/designers made bad choices back then no different than engineers/designers making bad choices today. The repairmen dealt with the issues as cheaply/quickly as possible, which does not mean people of the 80's couldn't comprehend the system.

Seriously? Who do you think repaired Pong (1972)? As if they even needed special training to track down missing grounds and locked coils. Whatever the scenario, it would not have been exclusive to Gottlieb machines. Expediency, not a lack of comprehension.