Record 50 and 6501 C3 Metal

[kbmonster]

Hello all, I've been looking for info on the metal used for the side plates, frame and star wheel in the Record 50 and 6501C3. I soaked both reels in water and purple power (PP) to degrease, got side tracked and know i have a brown "fuzz" on 95% of these pieces. Some areas retained the original "shine" so I'm wondering if the PP removed some special coating. The frame of the record is like new and the 6501 has that rough haze on it. I tried to remove it with Bar Keepers Friend and nothing changed, then i polished a side plate with Mother's Mag Polish and got most of the "shine" back, not like before but i can live with it.

Reels
Abu 6501 C3 - 2008
Abu Record 61 HC - 2006

The questions I'm looking for answers to are:
What metal are these components?
Are the side plates and frames the same material?
Is there a coating applied after production?
Can i get that look back?
If not any suggestions after polishing to keep that good look?

Here's a pic of the polished 50 side plate and furry components next to a 2006 R61HC.
I appreciate any help you can provide, links to this info is great for me too. Happy New Year!