Joe Hanson at LLO sent me a photo into their HEPI Fluid Reservoir interior so I wanted to check ours and did so this morning under WP 7040.  I was unable to capture an image but my observation would be that there was a little light dust-appearing patch (few cm²) on the surface and a few globules (drop size) on the walls of the vessel.  I think the surface patch could actually be dust on the surface and the globules on the sides are dried out fluid as the reservoir level has gone through level cycles.  This was at the Corner Station.  It saw no evidence of either at EndY and just the a small surface patch on the fluid at EndX.  What I saw was nothing like the image from LLO that I'll attach in a moment.  Have closed WP 7040.