Vacuumed in HAM2, using this combination of vaccum hoses:

• tiger vac
• vacuum hose covered in a new clean C3 cover
• adaptor that attaches to about 30 inches of plastic hose (~1.2inch, wiped outside and IPA run through the inside)
• Kapton tub

The Kapton tube was class-A, so I used it to vacuum horizontal surfaces in MC3, MC1, PR3, IM1, and IM3 cages, and I did use it in contact with the metal.

I kept close track of the space under the +Y MC3 blade spring, and from this test area I can see that larger particulate are picked up by the vacuum, but smaller particulate are not, and when I wipe with a IPA wipe, the small particulate are removed.  Picture attached.

I put IM1 on EQ stops and used the vacuum to remove a large particle on the upper portion of the face of IM1, and this was successful without any contact between the optic and the Kapton tube.

I used the same technique to remove large particulate from the MC REFL periscope 2 lower mirror, which was very contaminated.  Not all of the particulate that I could see would come off of the optic, so some may be scratches that have been present since install.

Given my conclusion that vacuuming leaves small particulate, I wiped over all of the surfaces that I could reach in HAM2 from both the West and East doors.

PRM stage M2 has OSEM flags on the HR side of the tower that do not go into OSEMS, and the -Y flag has shifted out of place, and will need to be restored.

The really big story is that IM1, IM2, and IM3 shifted in alignment between 50 and 1500urad, and I have only one explanation for this, which is that the 4 8/32 bolts that hold the top plate to the side plates are loose, and will need to be tightened.

These bolts are covered by the brackets that hold the blade spring EQ stops at the top of the tower, so the brackets will need to come off to give access to the remaining 4 loose bolts.

This also reveals that the root cause of the shift I saw in IM3 after the B&K, a shift  I recreated myself by tapping with a dog clamp on the top plate, are these 4 hidden loose bolts.