PRIMARY mirror 

After taking with the vendor, Ken suggested to using swabs and alcohol on the big spots that we could see on the surface. I did that, and I was quite successful, except in one case, in which I only managed to spread the spot (see first picture). I tried hard to remove it, but no way, I only make it bigger (second picture). I stopped when I saw a black point appearing in the middle, as I was damaging the coating.  It is not a big deal, I think, because the "big spot" is on the edge of the surface. The rest of the surface looks better than before.


 Big folding mirror 

This one had a sticker on the barrel of the optic (see third picture). I scrub with liquinox + water forever, to try to remove the glue. Results in the forth picture. This might need another FTIR. As far as the surface is concerned, I had pretty much the same issues as for the primary mirror: some of the spots can be removed, some just spread and they damage the coating once you try hard to remove them. Again, I did that on the edge, it should be ok. 

 Secondary mirror 

The 5th picture shows the mirror before I started cleaning. It has a damage on the edge, and you can see the usual spots, but overall it seems better than the others. I scrub with liquinox on the barrel, and wipe down with methanol the surface. I didn't try to remove the spots.

 Small folding mirror 

Picture 6 shows the other folding mirror as it was before cleaning. As for the secondary, I didn't try to improve the surface.


 Conclusions  

With a couple of additional FTIR we should establish if these mirrors can go in vacuum. I don't think it is worth to try to improve the surfaces more, it is very easy to damage the coating.