Nick and Angel like to know if somebody has ever undone the rivet / washer? fixing of the flatened glide bullet of the window scissors (top left in the first photo, rear side with rivet second shot)
Anna
Anna,
Is that your helper in the top picture? 
and why would Nick and Angel want to do this to a rattey part???ed
Yes - Nick and Angel like to fetch tools or cut a cable… The Guinneas are like small dogs and walk around free - so they come around to see what I do - might be eatable… By the way- there is a film were a pig is eating an old "Trabant"as a running gag!
Still don’t know about the rivet, boys… 
Anna,
Looking at the design of the rivet it would not be hard to remove but I doubt that you would be able to use it again, a machine shop or someone with a lathe could make a replacement one easily though. Gently drill out the centre and or grind of the peened bit with a Dremel or similar, send it to me and I will fix it for you.
Tony W