Hey all!
These are a little odd. They are old enough to be before green board was common, but do have some ICs - is there any benefit to removing the excess junk/steel or are they stuck in low due to the board color?
Just for knowledge for these parts - "Electro-Flyte was a division of the Black Clawson Co. from mid 60's to mid 80's. They built and serviced their own DC drives and systems and then later used some ABB equipment."

I am side stepping your question. But. Look over those boards for any possible Axial Tantalums. Save them. They have value. I can see aluminum electrolyte. But. You may have some axial tants. Also. I suggest you google search some of those semiconductors. The transistors. Etc. Some are discontinued. Ohhhh. They can be valuable. I can post a story here. About trying to find an old discontinued Operational Amplifier. It had no substitute. Fairchild. Had to scrap out the entire input section to a commercial AM radio station. Thousands of dollars. Just for a 1.50 item in it's day. We even considered trying to hybrid some crazy circuitry to match input/output characteristics. Phewww! No time. You got to get a commercial broadcast site up and running. Business. I wasn't the chief engineer. But. What would the price tag be to get it up and running? A thousand for that Op Amp? It just happened to be visiting my friend. We both are FCC licensed. I heard about the problem and grabbed on that problem like a snapping turtle. I ended up at a nearby college. A Prof I knew. My conclusion. There is a reason some companies exist that are buying the old original photolithography. Etching. And depostion. "Rights" To manufacture the original IC die chip. And. This situation. In my opinion this was one of them. So. Check the entire population of components on any old PCBs. You just might have have something worth more than scrap.
Here to learn like everybody else.

You've got a lot of heavy low value metals on some of the boards and maybe copper connections lining the edge. So as is there's a range, probably low grade to low peripheral as is.

BUT, those Clare silver box components, need to be checked for mercury.

~~edit~~
Did a little searching, I can't find that they are mercury wetted relays, but do you're own research unless someone here can verify further.

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Here to learn more so I can recycle more
My grades are my own opinion and not an official grade from Boardsort