I've turned the main turbo back on and aligned the readout now.  The vacuum is already down to 1e-6torr.  It seems that the the offset pin on the bottom of the mass is causing the fiber to move a lot as the isolation mass rotates.  The movement does not appear much to the eye, but is taking up most of our readout range at the moment.

We can wait to see if this motion dies down.  If not we may be forced to replace this intermediate mass with one where the pin is in the center.