Asus Nexus 7 2nd gen disassembly and reassembly question

Hi,

I have a Nexus 7 2nd generation tablet with a broken screen that I'm replacing. I've completed the disassembly using Jullian Brown's guide and removed the broken screen from the bezel. As I was cleaning all traces of glue from the bezel (using WD40 as a solvent) a small black rubber gasket of some kind seems to have dropped off the bezel and I've unable to figure out where it came from. The piece is a rubber rectangle approximately 5mm x 4mm x 1mm and has a 1mm diameter hole slightly offset from the center. One side is flat while the flip side is recessed (so there's a rectangular ridge on the flip side that's maybe 0.5mm high). I took pictures of the bezel with the screen in place during the disassembly and in reviewing the pictures this gasket doesn't seem to be on the inside of the bezel so I'm guessing it must have been on the side of the bezel where the LCD screen was attached. I've still got the screen, though the edges are pretty broken up, and don't find any indication in the glue residue of where this gasket may have been (and again, I'm assuming it came off the screen side of the bezel). I am guessing this gasket was being held in place by glue residue and fell off while I was cleaning it. I'm hoping someone who's made this repair and is familiar with the Nexus 7 parts can tell me where it goes. I followed Jillian Brown's Nexus 7 2nd Generation LCD Screen Assembly Replacement guide to perform a complete disassembly and then used a heat-gun to soften the glue holding the screen to the bezel prior to removing the screen. The bezel has two cross struts about 5 cm in from the ends that the mother and daughter boards screw onto. These struts don't fit flush with the LCD/digitizer screen and the gasket looks to be the right thickness to fit between the struct and LCD screen so maybe that's where it fits (though I would expect there to be two of them ... unless one fell off I I didn't notice?). Thanks in advance.