Alexa and I mounted the PD interface box on the new end Y table this morning.  We used brackets from Mcmaster, and 2 inch long 10-32 bolts from the mechanical room.   The bolts are long enough that the box hangs just below the lights.  This is a little different from what they've done at LLO  LLO alog 8847 , but it works with the brackets we have.  We turned the box around with respect to the way it is on the ISCEX table, so that it will be easier to reach the connectors when the HWS interface box is installed. This is the position we had in mind when we measured the cable lengths. 

The last image attached is the ISCEX table, with the HWS interface box already installed just for reference.