The loose cassette cover plate has a very small effect on beam position

After CD013, we found that the cassette cover plate was loose - all the screws along the perimeter had a gap of about 1/16" (see photo above). We haven't seen this in any other component of the system, so we suppose these screws were untightened during the button-up before CD013. How big an effect does this have on the beam position at the detector?

Using the red HeNe laser, I acquired the laser beam in medium resolution mode (see image below).
I took a few images with the plate allowed to hang freely on the screws. Then I pushed on the far side of the plate so that there was only a gap on the near side. Then I pushed in the entire plate, so that there was no gap along the entire perimeter.

All files are in B_12_04_02/
image number            comment
b008-009            plate allowed to "hang"
b010-011            pushed in on far side (as seen in blog photo of cover plate)
b012-014            plate pushed in on all sides

The deflections were very small:
with respect to the beam position when the plate was allowed to hang:
when the plate was pushed on far side, beam moved ~4 pix in x
when the plate was pushed on all sides, beam moved ~ -6 pix in y