I went into Ebay and found some left footpegs and brackets.
Unfortunately for the $$ they want for the used parts you can almost buy the new. All shown here.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2499334.m570.l1313&_nkw=left+foot+peg+zg-1000&_sacat=10063

I'm picking up a crashed C-10 next month (for the engine).
If it has the left peg, I'll let you know.

Ride safe, Ted

I'm pretty certain that that particular bolt is only used to hold the front calipers onto the fork lowers.
Are you sure that you haven't replaced them with better quality aftermarket bolts and that is one of the originals?

As for the nut/washer, could be from just about anywhere but I would check the engine mount bolts, especially if you have fitted crash bars, although those are M10/M12 nuts and the one you have seems to be an M8 like the caliper bolt.
Otherwise, if you have "friends" who like a joke and also have a C14, then I would suspect them of dirty tricks. 

$100 will get it picked up. 

Bump

I've taken pics of individual parts for listing on ebay but, as stated, would rather just let it all go for a reasonable offer.  There's various imperfections in the custom paint and pinstripe job, some repairs, a pinhole in the tank, etc.