List Images On DiskPool Before Phase I Import

Is there a way to query a diskpool to get a list of images on it before I initiate a Phase I import? 
I am hesitant to run the Phase I import until I have time to finish the Phase II import as I have been burned in the past where NBU will expire the images off disk because the Phase I sets a 1 week retention on the images in the catalog.
The diskpool I want to query if from a legacy NBU environment that has been decommisioned.
 

I was hoping I could use bpstsinfo to grab the info, but it requires a mediaid which isn't created until Phase I

NBU 7.6.0.2 on RHL