Starting to scrap for local Computer/technology company

so there is a local company that specializes in scrapping computer related equipment and I have no idea what they do with all the the parts they get from each unit. I'm guessing that they may get some low amount of scrap fee for various parts, like selling RAM, CPU, HD's and some other stuff. On top of this they also have networking equipment (both residential and commercial/professional).

I have a wall about 8ft tall and 20ft long full of servers and networking equipment which i have been putting off taking apart and possibly listing some items for sale if I can find a place where they can be sold without major fees like on Fleabay.

I'm interested especially in UPS backup (especially the higher VA high wattage units from 1500va to 10,000va+) to see if they an be salvageable or if can pull some components from the units such as good capacitors, transformers, inductors and maybe some mosfets, triacs and other solid state transistors. IDk what else could be worth pulling from these but if anyone has any suggestions I would appreciate it!

This place also has desktops, all kinds of printers from lasers, desktops,scanners, 3 in 1, copiers, phone systems, network equipment (professional routers, switches, etc).

I was thinking about trying to salvage the sliding mounting racks for each server or unit. These could be put into a custom built (19" wide standard, but maybe 26-28" tall) drawer cabinet where the old cases of the servers, UPS's, network equipment ,etc can be used as the drawers for the cabinets. These would be pretty heavy duty and could be as deep as 3 feet!1 but

I'd realy lke tofid out what the composition of the hard drive cases are if they are solid aluminum or some blend of Al/Mg as well as the cover plate which ins some cases seems to be stainless but it is often a laminated (many layers glued together) and many are non-magnetic.

Finally the super shiny hard drive platters, who knows what they are made of, I've heard Al with a platinum coating,some say paladium coating and others just say aluminum. Well I've shot at these with a 22 mag rifle as well as a 9mm P+ from a carbine and with a direct hit it only damages 2-3 plates (each are still mounted on hard drive with about 5-10mm space in between platters. This seems to suggest a VERY strong metal which I need to figure out what it is b/c I'm collecting them until I figure out what they are.

I could also be running into LCD monitors, Plasma TV's, and basically any electronics from the last 30 years. Any idea on what to look out for or suggestions about the questions posed above?