Today, I applied FC to the MCe mirror to remove the contamination spots near the center.

First, I locked the mirror with EQ stops.

Then I blew ionized air into the mirror surface to remove dusts on it.
It did not change the stains near the center.
(attachment #1)

Then I put a Vectra Alpha near the bottom to catch droplets of FC.
(attachment #2, #3)

After pouring the FC into a bowl, I waited for about 2min to increase the viscousity of the FC liquid.
Then I applied the FC near the center with a brush.
I also put a peel tab on it.
(attachment #4)

After about 45min, I peeled the dried FC.
I also used an ion gun to blow away any dust attracted by the electrostatic.
Unfortunately, there was a tiny patch of FC remaining on the surface. 
So I applied a small amout of the FC on it and peeled off after 20min to completely remove the FC.

The photo after the cleaning with FC did not show any improvemnt on the stains.
(attachment #5)
So, these spots are not dusts, because dusts should be easily removed by the FC.
Probably, these stains were there before we opened the MC chambers this time.
If so, the MC finesse was good even with those stain spots. So we will not try to remove those spots further.

I also took photos of MCi and MCo with focus on the center of the mirror.
(attachment #6(MCi), #7(MCo))
There are actually stain spots similar to the MCe mirror.
Probably they are also not removable with the FC. 
So we decided to leave them as is.

After this work, I returned the Top Gun of CRY to the front room of IXC.
The mirror surface inspection kit, including a remote controllable camera, is in the front room near PR3.