I honestly don't know about that bracket sorry, but it can be said that more than MZ parts might be in your boxes! I recently sold a ton of old Honda CX500 parts, which I had listed as such on eBay, but there were more than just honda parts.. lots of other random crap I didn't want or need, or applied to the bike in question- just wanted them all gone.. So... keep it for now, but be weary of this fact.
As for bins, for me, one is general waste (goes in black bags then in the bin), and the other bin is for ANYTHING recyclable - cardboard, glass, plastic etc. But.. actually, I put anything in there- so long as most of the stuff that should not be recycled is at the bottom..
There is a food waste day too, but I just chuck any food waste in the general bin.